* Removed `script.default_lang` setting and made `painless` the hardcoded default script language.

** The default script language is now maintained in `Script` class.
* Added `script.legacy.default_lang` setting that controls the default language for scripts that are stored inside documents (for example percolator queries).  This defaults to groovy.
** Added `QueryParseContext#getDefaultScriptLanguage()` that manages the default scripting language. Returns always `painless`, unless loading query/search request in legacy mode then the returns what is configured in `script.legacy.default_lang` setting.
** In the aggregation parsing code added `ParserContext` that also holds the default scripting language like `QueryParseContext`. Most parser don't have access to `QueryParseContext`. This is for scripts in aggregations.
* The `lang` script field is always serialized (toXContent).

Closes #20122

core/src/main/java/org/elasticsearch/index/query/QueryParseContext.java

@@ -25,8 +25,11 @@ import org.elasticsearch.common.ParseFieldMatcherSupplier;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.Loggers;
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.indices.query.IndicesQueriesRegistry;
+import org.elasticsearch.script.Script;
+import org.elasticsearch.script.ScriptSettings;
 
 import java.io.IOException;
 import java.util.Objects;
@@ -42,11 +45,18 @@ public class QueryParseContext implements ParseFieldMatcherSupplier {
     private final XContentParser parser;
     private final IndicesQueriesRegistry indicesQueriesRegistry;
     private final ParseFieldMatcher parseFieldMatcher;
+    private final String defaultScriptLanguage;
 
     public QueryParseContext(IndicesQueriesRegistry registry, XContentParser parser, ParseFieldMatcher parseFieldMatcher) {
+        this(Script.DEFAULT_SCRIPT_LANG, registry, parser, parseFieldMatcher);
+    }
+
+    public QueryParseContext(String defaultScriptLanguage, IndicesQueriesRegistry registry, XContentParser parser,
+                             ParseFieldMatcher parseFieldMatcher) {
         this.indicesQueriesRegistry = Objects.requireNonNull(registry, "indices queries registry cannot be null");
         this.parser = Objects.requireNonNull(parser, "parser cannot be null");
         this.parseFieldMatcher = Objects.requireNonNull(parseFieldMatcher, "parse field matcher cannot be null");
+        this.defaultScriptLanguage = defaultScriptLanguage;
     }
 
     public XContentParser parser() {
@@ -127,4 +137,12 @@ public class QueryParseContext implements ParseFieldMatcherSupplier {
     public ParseFieldMatcher getParseFieldMatcher() {
         return parseFieldMatcher;
     }
+
+    /**
+     * Returns the default scripting language, that should be used if scripts don't specify the script language
+     * explicitly.
+     */
+    public String getDefaultScriptLanguage() {
+        return defaultScriptLanguage;
+    }
 }

core/src/main/java/org/elasticsearch/index/query/QueryRewriteContext.java

@@ -28,6 +28,7 @@ import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.indices.query.IndicesQueriesRegistry;
 import org.elasticsearch.script.ScriptService;
+import org.elasticsearch.script.ScriptSettings;
 
 /**
  * Context object used to rewrite {@link QueryBuilder} instances into simplified version.
@@ -101,9 +102,18 @@ public class QueryRewriteContext implements ParseFieldMatcherSupplier {
 
     /**
      * Returns a new {@link QueryParseContext} that wraps the provided parser, using the ParseFieldMatcher settings that
-     * are configured in the index settings
+     * are configured in the index settings. The default script language will always default to Painless.
      */
     public QueryParseContext newParseContext(XContentParser parser) {
         return new QueryParseContext(indicesQueriesRegistry, parser, indexSettings.getParseFieldMatcher());
     }
+
+    /**
+     * Returns a new {@link QueryParseContext} like {@link #newParseContext(XContentParser)} with the only diffence, that
+     * the default script language will default to what has been set in the 'script.legacy.default_lang' setting.
+     */
+    public QueryParseContext newParseContextWithLegacyScriptLanguage(XContentParser parser) {
+        String defaultScriptLanguage = ScriptSettings.getLegacyDefaultLang(indexSettings.getNodeSettings());
+        return new QueryParseContext(defaultScriptLanguage, indicesQueriesRegistry, parser, indexSettings.getParseFieldMatcher());
+    }
 }

core/src/main/java/org/elasticsearch/index/query/ScriptQueryBuilder.java

@@ -106,7 +106,7 @@ public class ScriptQueryBuilder extends AbstractQueryBuilder<ScriptQueryBuilder>
                 // skip
             } else if (token == XContentParser.Token.START_OBJECT) {
                 if (parseContext.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, parseContext.getParseFieldMatcher());
+                    script = Script.parse(parser, parseContext.getParseFieldMatcher(), parseContext.getDefaultScriptLanguage());
                 } else {
                     throw new ParsingException(parser.getTokenLocation(), "[script] query does not support [" + currentFieldName + "]");
                 }
@@ -116,7 +116,7 @@ public class ScriptQueryBuilder extends AbstractQueryBuilder<ScriptQueryBuilder>
                 } else if (parseContext.getParseFieldMatcher().match(currentFieldName, AbstractQueryBuilder.BOOST_FIELD)) {
                     boost = parser.floatValue();
                 } else if (parseContext.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, parseContext.getParseFieldMatcher());
+                    script = Script.parse(parser, parseContext.getParseFieldMatcher(), parseContext.getDefaultScriptLanguage());
                 } else {
                     throw new ParsingException(parser.getTokenLocation(), "[script] query does not support [" + currentFieldName + "]");
                 }

core/src/main/java/org/elasticsearch/index/query/functionscore/ScriptScoreFunctionBuilder.java

@@ -115,7 +115,7 @@ public class ScriptScoreFunctionBuilder extends ScoreFunctionBuilder<ScriptScore
                 currentFieldName = parser.currentName();
             } else {
                 if (parseContext.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, parseContext.getParseFieldMatcher());
+                    script = Script.parse(parser, parseContext.getParseFieldMatcher(), parseContext.getDefaultScriptLanguage());
                 } else {
                     throw new ParsingException(parser.getTokenLocation(), NAME + " query does not support [" + currentFieldName + "]");
                 }

core/src/main/java/org/elasticsearch/script/Script.java

@@ -44,6 +44,7 @@ import java.util.Objects;
 public final class Script implements ToXContent, Writeable {
 
     public static final ScriptType DEFAULT_TYPE = ScriptType.INLINE;
+    public static final String DEFAULT_SCRIPT_LANG = "painless";
 
     private String script;
     private ScriptType type;
@@ -60,7 +61,7 @@ public final class Script implements ToXContent, Writeable {
         this(script, ScriptType.INLINE, null, null);
     }
 
-    public Script(String script, ScriptType type, @Nullable String lang, @Nullable Map<String, ?> params) {
+    public Script(String script, ScriptType type, String lang, @Nullable Map<String, ?> params) {
         this(script, type, lang, params, null);
     }
 
@@ -78,14 +79,14 @@ public final class Script implements ToXContent, Writeable {
      *                      when serializing the script back to xcontent.
      */
     @SuppressWarnings("unchecked")
-    public Script(String script, ScriptType type, @Nullable String lang, @Nullable Map<String, ?> params,
+    public Script(String script, ScriptType type, String lang, @Nullable Map<String, ?> params,
                   @Nullable XContentType  contentType) {
         if (contentType != null && type != ScriptType.INLINE) {
             throw new IllegalArgumentException("The parameter contentType only makes sense for inline scripts");
         }
         this.script = Objects.requireNonNull(script);
         this.type = Objects.requireNonNull(type);
-        this.lang = lang;
+        this.lang = lang == null ? DEFAULT_SCRIPT_LANG : lang;
         this.params = (Map<String, Object>) params;
         this.contentType = contentType;
     }
@@ -135,7 +136,7 @@ public final class Script implements ToXContent, Writeable {
      * @return The type of script -- inline, stored, or file.
      */
     public ScriptType getType() {
-        return type == null ? DEFAULT_TYPE : type;
+        return type;
     }
 
     /**
@@ -196,7 +197,7 @@ public final class Script implements ToXContent, Writeable {
             token = parser.nextToken();
         }
         if (token == XContentParser.Token.VALUE_STRING) {
-            return new Script(parser.text());
+            return new Script(parser.text(), ScriptType.INLINE, lang, null);
         }
         if (token != XContentParser.Token.START_OBJECT) {
             throw new ElasticsearchParseException("expected a string value or an object, but found [{}] instead", token);

core/src/main/java/org/elasticsearch/script/ScriptService.java

@@ -92,8 +92,6 @@ public class ScriptService extends AbstractComponent implements Closeable, Clust
     public static final Setting<Integer> SCRIPT_MAX_COMPILATIONS_PER_MINUTE =
         Setting.intSetting("script.max_compilations_per_minute", 15, 0, Property.Dynamic, Property.NodeScope);
 
-    private final String defaultLang;
-
     private final Collection<ScriptEngineService> scriptEngines;
     private final Map<String, ScriptEngineService> scriptEnginesByLang;
     private final Map<String, ScriptEngineService> scriptEnginesByExt;
@@ -131,8 +129,6 @@ public class ScriptService extends AbstractComponent implements Closeable, Clust
         this.scriptContextRegistry = scriptContextRegistry;
         int cacheMaxSize = SCRIPT_CACHE_SIZE_SETTING.get(settings);
 
-        this.defaultLang = scriptSettings.getDefaultScriptLanguageSetting().get(settings);
-
         CacheBuilder<CacheKey, CompiledScript> cacheBuilder = CacheBuilder.builder();
         if (cacheMaxSize >= 0) {
             cacheBuilder.setMaximumWeight(cacheMaxSize);
@@ -222,11 +218,6 @@ public class ScriptService extends AbstractComponent implements Closeable, Clust
         }
 
         String lang = script.getLang();
-
-        if (lang == null) {
-            lang = defaultLang;
-        }
-
         ScriptEngineService scriptEngineService = getScriptEngineServiceForLang(lang);
         if (canExecuteScript(lang, script.getType(), scriptContext) == false) {
             throw new IllegalStateException("scripts of type [" + script.getType() + "], operation [" + scriptContext.getKey() + "] and lang [" + lang + "] are disabled");
@@ -285,7 +276,7 @@ public class ScriptService extends AbstractComponent implements Closeable, Clust
             throw new IllegalArgumentException("The parameter script (Script) must not be null.");
         }
 
-        String lang = script.getLang() == null ? defaultLang : script.getLang();
+        String lang = script.getLang();
         ScriptType type = script.getType();
         //script.getScript() could return either a name or code for a script,
         //but we check for a file script name first and an indexed script name second
@@ -364,9 +355,8 @@ public class ScriptService extends AbstractComponent implements Closeable, Clust
     }
 
     private String validateScriptLanguage(String scriptLang) {
-        if (scriptLang == null) {
-            scriptLang = defaultLang;
-        } else if (scriptEnginesByLang.containsKey(scriptLang) == false) {
+        Objects.requireNonNull(scriptLang);
+        if (scriptEnginesByLang.containsKey(scriptLang) == false) {
             throw new IllegalArgumentException("script_lang not supported [" + scriptLang + "]");
         }
         return scriptLang;

core/src/main/java/org/elasticsearch/script/ScriptSettings.java

@@ -32,7 +32,16 @@ import java.util.function.Function;
 
 public class ScriptSettings {
 
-    public static final String DEFAULT_LANG = "painless";
+    static final String LEGACY_DEFAULT_LANG = "groovy";
+
+    /**
+     * The default script language to use for scripts that are stored in documents that have no script lang set explicitly.
+     * This setting is legacy setting and only applies for indices created on ES versions prior to version 5.0
+     *
+     * This constant will be removed in the next major release.
+     */
+    @Deprecated
+    public static final String LEGACY_SCRIPT_SETTING = "script.legacy.default_lang";
 
     private static final Map<ScriptService.ScriptType, Setting<Boolean>> SCRIPT_TYPE_SETTING_MAP;
 
@@ -49,7 +58,7 @@ public class ScriptSettings {
 
     private final Map<ScriptContext, Setting<Boolean>> scriptContextSettingMap;
     private final List<Setting<Boolean>> scriptLanguageSettings;
-    private final Setting<String> defaultScriptLanguageSetting;
+    private final Setting<String> defaultLegacyScriptLanguageSetting;
 
     public ScriptSettings(ScriptEngineRegistry scriptEngineRegistry, ScriptContextRegistry scriptContextRegistry) {
         Map<ScriptContext, Setting<Boolean>> scriptContextSettingMap = contextSettings(scriptContextRegistry);
@@ -58,8 +67,8 @@ public class ScriptSettings {
         List<Setting<Boolean>> scriptLanguageSettings = languageSettings(SCRIPT_TYPE_SETTING_MAP, scriptContextSettingMap, scriptEngineRegistry, scriptContextRegistry);
         this.scriptLanguageSettings = Collections.unmodifiableList(scriptLanguageSettings);
 
-        this.defaultScriptLanguageSetting = new Setting<>("script.default_lang", DEFAULT_LANG, setting -> {
-            if (!DEFAULT_LANG.equals(setting) && !scriptEngineRegistry.getRegisteredLanguages().containsKey(setting)) {
+        this.defaultLegacyScriptLanguageSetting = new Setting<>(LEGACY_SCRIPT_SETTING, LEGACY_DEFAULT_LANG, setting -> {
+            if (!LEGACY_DEFAULT_LANG.equals(setting) && !scriptEngineRegistry.getRegisteredLanguages().containsKey(setting)) {
                 throw new IllegalArgumentException("unregistered default language [" + setting + "]");
             }
             return setting;
@@ -160,7 +169,7 @@ public class ScriptSettings {
         settings.addAll(SCRIPT_TYPE_SETTING_MAP.values());
         settings.addAll(scriptContextSettingMap.values());
         settings.addAll(scriptLanguageSettings);
-        settings.add(defaultScriptLanguageSetting);
+        settings.add(defaultLegacyScriptLanguageSetting);
         return settings;
     }
 
@@ -168,7 +177,11 @@ public class ScriptSettings {
         return scriptLanguageSettings;
     }
 
-    public Setting<String> getDefaultScriptLanguageSetting() {
-        return defaultScriptLanguageSetting;
+    public Setting<String> getDefaultLegacyScriptLanguageSetting() {
+        return defaultLegacyScriptLanguageSetting;
+    }
+
+    public static String getLegacyDefaultLang(Settings settings) {
+        return settings.get(LEGACY_SCRIPT_SETTING, ScriptSettings.LEGACY_DEFAULT_LANG);
     }
 }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoHashGridParser.java

@@ -19,11 +19,11 @@
 package org.elasticsearch.search.aggregations.bucket.geogrid;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.index.query.GeoBoundingBoxQueryBuilder;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.GeoPointValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -65,16 +65,17 @@ public class GeoHashGridParser extends GeoPointValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
         if (token == XContentParser.Token.VALUE_NUMBER || token == XContentParser.Token.VALUE_STRING) {
-            if (parseFieldMatcher.match(currentFieldName, GeoHashGridParams.FIELD_PRECISION)) {
+            if (context.matchField(currentFieldName, GeoHashGridParams.FIELD_PRECISION)) {
                 otherOptions.put(GeoHashGridParams.FIELD_PRECISION, parser.intValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, GeoHashGridParams.FIELD_SIZE)) {
+            } else if (context.matchField(currentFieldName, GeoHashGridParams.FIELD_SIZE)) {
                 otherOptions.put(GeoHashGridParams.FIELD_SIZE, parser.intValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, GeoHashGridParams.FIELD_SHARD_SIZE)) {
+            } else if (context.matchField(currentFieldName, GeoHashGridParams.FIELD_SHARD_SIZE)) {
                 otherOptions.put(GeoHashGridParams.FIELD_SHARD_SIZE, parser.intValue());
                 return true;
             }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramParser.java

@@ -19,11 +19,11 @@
 package org.elasticsearch.search.aggregations.bucket.histogram;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -79,10 +79,11 @@ public class DateHistogramParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
         if (token.isValue()) {
-            if (parseFieldMatcher.match(currentFieldName, Histogram.INTERVAL_FIELD)) {
+            if (context.matchField(currentFieldName, Histogram.INTERVAL_FIELD)) {
                 if (token == XContentParser.Token.VALUE_STRING) {
                     otherOptions.put(Histogram.INTERVAL_FIELD, new DateHistogramInterval(parser.text()));
                     return true;
@@ -90,13 +91,13 @@ public class DateHistogramParser extends NumericValuesSourceParser {
                     otherOptions.put(Histogram.INTERVAL_FIELD, parser.longValue());
                     return true;
                 }
-            } else if (parseFieldMatcher.match(currentFieldName, Histogram.MIN_DOC_COUNT_FIELD)) {
+            } else if (context.matchField(currentFieldName, Histogram.MIN_DOC_COUNT_FIELD)) {
                 otherOptions.put(Histogram.MIN_DOC_COUNT_FIELD, parser.longValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, Histogram.KEYED_FIELD)) {
+            } else if (context.matchField(currentFieldName, Histogram.KEYED_FIELD)) {
                 otherOptions.put(Histogram.KEYED_FIELD, parser.booleanValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, Histogram.OFFSET_FIELD)) {
+            } else if (context.matchField(currentFieldName, Histogram.OFFSET_FIELD)) {
                 if (token == XContentParser.Token.VALUE_STRING) {
                     otherOptions.put(Histogram.OFFSET_FIELD,
                             DateHistogramAggregationBuilder.parseStringOffset(parser.text()));
@@ -109,7 +110,7 @@ public class DateHistogramParser extends NumericValuesSourceParser {
                 return false;
             }
         } else if (token == XContentParser.Token.START_OBJECT) {
-            if (parseFieldMatcher.match(currentFieldName, Histogram.ORDER_FIELD)) {
+            if (context.matchField(currentFieldName, Histogram.ORDER_FIELD)) {
                 InternalOrder order = null;
                 while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                     if (token == XContentParser.Token.FIELD_NAME) {
@@ -127,9 +128,10 @@ public class DateHistogramParser extends NumericValuesSourceParser {
                 }
                 otherOptions.put(Histogram.ORDER_FIELD, order);
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, ExtendedBounds.EXTENDED_BOUNDS_FIELD)) {
+            } else if (context.matchField(currentFieldName, ExtendedBounds.EXTENDED_BOUNDS_FIELD)) {
                 try {
-                    otherOptions.put(ExtendedBounds.EXTENDED_BOUNDS_FIELD, ExtendedBounds.PARSER.apply(parser, () -> parseFieldMatcher));
+                    otherOptions.put(ExtendedBounds.EXTENDED_BOUNDS_FIELD,
+                            ExtendedBounds.PARSER.apply(parser, context::getParseFieldMatcher));
                 } catch (Exception e) {
                     throw new ParsingException(parser.getTokenLocation(), "Error parsing [{}]", e, aggregationName);
                 }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/HistogramParser.java

@@ -19,13 +19,13 @@
 package org.elasticsearch.search.aggregations.bucket.histogram;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.ParseFieldMatcherSupplier;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -85,26 +85,27 @@ public class HistogramParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
         if (token.isValue()) {
-            if (parseFieldMatcher.match(currentFieldName, Histogram.INTERVAL_FIELD)) {
+            if (context.matchField(currentFieldName, Histogram.INTERVAL_FIELD)) {
                 otherOptions.put(Histogram.INTERVAL_FIELD, parser.doubleValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, Histogram.MIN_DOC_COUNT_FIELD)) {
+            } else if (context.matchField(currentFieldName, Histogram.MIN_DOC_COUNT_FIELD)) {
                 otherOptions.put(Histogram.MIN_DOC_COUNT_FIELD, parser.longValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, Histogram.KEYED_FIELD)) {
+            } else if (context.matchField(currentFieldName, Histogram.KEYED_FIELD)) {
                 otherOptions.put(Histogram.KEYED_FIELD, parser.booleanValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, Histogram.OFFSET_FIELD)) {
+            } else if (context.matchField(currentFieldName, Histogram.OFFSET_FIELD)) {
                 otherOptions.put(Histogram.OFFSET_FIELD, parser.doubleValue());
                 return true;
             } else {
                 return false;
             }
         } else if (token == XContentParser.Token.START_OBJECT) {
-            if (parseFieldMatcher.match(currentFieldName, Histogram.ORDER_FIELD)) {
+            if (context.matchField(currentFieldName, Histogram.ORDER_FIELD)) {
                 InternalOrder order = null;
                 while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                     if (token == XContentParser.Token.FIELD_NAME) {
@@ -122,8 +123,8 @@ public class HistogramParser extends NumericValuesSourceParser {
                 }
                 otherOptions.put(Histogram.ORDER_FIELD, order);
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, Histogram.EXTENDED_BOUNDS_FIELD)) {
-                double[] bounds = EXTENDED_BOUNDS_PARSER.apply(parser, () -> parseFieldMatcher);
+            } else if (context.matchField(currentFieldName, Histogram.EXTENDED_BOUNDS_FIELD)) {
+                double[] bounds = EXTENDED_BOUNDS_PARSER.apply(parser, context::getParseFieldMatcher);
                 otherOptions.put(Histogram.EXTENDED_BOUNDS_FIELD, bounds);
                 return true;
             } else {

core/src/main/java/org/elasticsearch/search/aggregations/bucket/missing/MissingParser.java

@@ -19,9 +19,9 @@
 package org.elasticsearch.search.aggregations.bucket.missing;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.AnyValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -35,8 +35,8 @@ public class MissingParser extends AnyValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/bucket/range/RangeParser.java

@@ -24,6 +24,7 @@ import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.bucket.range.RangeAggregator.Range;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -65,20 +66,21 @@ public class RangeParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
         if (token == XContentParser.Token.START_ARRAY) {
-            if (parseFieldMatcher.match(currentFieldName, RangeAggregator.RANGES_FIELD)) {
+            if (context.matchField(currentFieldName, RangeAggregator.RANGES_FIELD)) {
                 List<Range> ranges = new ArrayList<>();
                 while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
-                    Range range = parseRange(parser, parseFieldMatcher);
+                    Range range = parseRange(parser, context.getParseFieldMatcher());
                     ranges.add(range);
                 }
                 otherOptions.put(RangeAggregator.RANGES_FIELD, ranges);
                 return true;
             }
         } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
-            if (parseFieldMatcher.match(currentFieldName, RangeAggregator.KEYED_FIELD)) {
+            if (context.matchField(currentFieldName, RangeAggregator.KEYED_FIELD)) {
                 boolean keyed = parser.booleanValue();
                 otherOptions.put(RangeAggregator.KEYED_FIELD, keyed);
                 return true;

core/src/main/java/org/elasticsearch/search/aggregations/bucket/range/geodistance/GeoDistanceParser.java

@@ -19,7 +19,6 @@
 package org.elasticsearch.search.aggregations.bucket.range.geodistance;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.geo.GeoDistance;
 import org.elasticsearch.common.geo.GeoPoint;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -30,6 +29,7 @@ import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.bucket.range.RangeAggregator;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.GeoPointValuesSourceParser;
 import org.elasticsearch.search.aggregations.support.GeoPointParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -110,28 +110,29 @@ public class GeoDistanceParser extends GeoPointValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
-        if (geoPointParser.token(aggregationName, currentFieldName, token, parser, parseFieldMatcher, otherOptions)) {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
+        if (geoPointParser.token(aggregationName, currentFieldName, token, parser, context.getParseFieldMatcher(), otherOptions)) {
             return true;
         } else if (token == XContentParser.Token.VALUE_STRING) {
-            if (parseFieldMatcher.match(currentFieldName, UNIT_FIELD)) {
+            if (context.matchField(currentFieldName, UNIT_FIELD)) {
                 DistanceUnit unit = DistanceUnit.fromString(parser.text());
                 otherOptions.put(UNIT_FIELD, unit);
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, DISTANCE_TYPE_FIELD)) {
+            } else if (context.matchField(currentFieldName, DISTANCE_TYPE_FIELD)) {
                 GeoDistance distanceType = GeoDistance.fromString(parser.text());
                 otherOptions.put(DISTANCE_TYPE_FIELD, distanceType);
                 return true;
             }
         } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
-            if (parseFieldMatcher.match(currentFieldName, RangeAggregator.KEYED_FIELD)) {
+            if (context.matchField(currentFieldName, RangeAggregator.KEYED_FIELD)) {
                 boolean keyed = parser.booleanValue();
                 otherOptions.put(RangeAggregator.KEYED_FIELD, keyed);
                 return true;
             }
         } else if (token == XContentParser.Token.START_ARRAY) {
-            if (parseFieldMatcher.match(currentFieldName, RangeAggregator.RANGES_FIELD)) {
+            if (context.matchField(currentFieldName, RangeAggregator.RANGES_FIELD)) {
                 List<Range> ranges = new ArrayList<>();
                 while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
                     String fromAsStr = null;
@@ -144,17 +145,17 @@ public class GeoDistanceParser extends GeoPointValuesSourceParser {
                         if (token == XContentParser.Token.FIELD_NAME) {
                             toOrFromOrKey = parser.currentName();
                         } else if (token == XContentParser.Token.VALUE_NUMBER) {
-                            if (parseFieldMatcher.match(toOrFromOrKey, Range.FROM_FIELD)) {
+                            if (context.matchField(toOrFromOrKey, Range.FROM_FIELD)) {
                                 from = parser.doubleValue();
-                            } else if (parseFieldMatcher.match(toOrFromOrKey, Range.TO_FIELD)) {
+                            } else if (context.matchField(toOrFromOrKey, Range.TO_FIELD)) {
                                 to = parser.doubleValue();
                             }
                         } else if (token == XContentParser.Token.VALUE_STRING) {
-                            if (parseFieldMatcher.match(toOrFromOrKey, Range.KEY_FIELD)) {
+                            if (context.matchField(toOrFromOrKey, Range.KEY_FIELD)) {
                                 key = parser.text();
-                            } else if (parseFieldMatcher.match(toOrFromOrKey, Range.FROM_FIELD)) {
+                            } else if (context.matchField(toOrFromOrKey, Range.FROM_FIELD)) {
                                 fromAsStr = parser.text();
-                            } else if (parseFieldMatcher.match(toOrFromOrKey, Range.TO_FIELD)) {
+                            } else if (context.matchField(toOrFromOrKey, Range.TO_FIELD)) {
                                 toAsStr = parser.text();
                             }
                         }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/range/ip/IpRangeParser.java

@@ -31,6 +31,7 @@ import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.BytesValuesSourceParser;
 import org.elasticsearch.search.aggregations.bucket.range.RangeAggregator;
 import org.elasticsearch.search.aggregations.bucket.range.ip.IpRangeAggregationBuilder.Range;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregationBuilder;
@@ -102,21 +103,22 @@ public class IpRangeParser extends BytesValuesSourceParser {
 
     @Override
     protected boolean token(String aggregationName, String currentFieldName,
-            Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher,
-            Map<ParseField, Object> otherOptions) throws IOException {
-        if (parseFieldMatcher.match(currentFieldName, RangeAggregator.RANGES_FIELD)) {
+                            Token token,
+                            XContentParseContext context,
+                            Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
+        if (context.matchField(currentFieldName, RangeAggregator.RANGES_FIELD)) {
             if (parser.currentToken() != Token.START_ARRAY) {
                 throw new ParsingException(parser.getTokenLocation(), "[ranges] must be passed as an array, but got a " + token);
             }
             List<Range> ranges = new ArrayList<>();
             while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
-                Range range = parseRange(parser, parseFieldMatcher);
+                Range range = parseRange(parser, context.getParseFieldMatcher());
                 ranges.add(range);
             }
             otherOptions.put(RangeAggregator.RANGES_FIELD, ranges);
             return true;
-        } else if (parseFieldMatcher.match(parser.currentName(), RangeAggregator.KEYED_FIELD)) {
+        } else if (context.matchField(parser.currentName(), RangeAggregator.KEYED_FIELD)) {
             otherOptions.put(RangeAggregator.KEYED_FIELD, parser.booleanValue());
             return true;
         }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/sampler/DiversifiedSamplerParser.java

@@ -20,9 +20,9 @@ package org.elasticsearch.search.aggregations.bucket.sampler;
 
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.AnyValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -57,20 +57,21 @@ public class DiversifiedSamplerParser extends AnyValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
         if (token == XContentParser.Token.VALUE_NUMBER) {
-            if (parseFieldMatcher.match(currentFieldName, SamplerAggregator.SHARD_SIZE_FIELD)) {
+            if (context.matchField(currentFieldName, SamplerAggregator.SHARD_SIZE_FIELD)) {
                 int shardSize = parser.intValue();
                 otherOptions.put(SamplerAggregator.SHARD_SIZE_FIELD, shardSize);
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, SamplerAggregator.MAX_DOCS_PER_VALUE_FIELD)) {
+            } else if (context.matchField(currentFieldName, SamplerAggregator.MAX_DOCS_PER_VALUE_FIELD)) {
                 int maxDocsPerValue = parser.intValue();
                 otherOptions.put(SamplerAggregator.MAX_DOCS_PER_VALUE_FIELD, maxDocsPerValue);
                 return true;
             }
         } else if (token == XContentParser.Token.VALUE_STRING) {
-            if (parseFieldMatcher.match(currentFieldName, SamplerAggregator.EXECUTION_HINT_FIELD)) {
+            if (context.matchField(currentFieldName, SamplerAggregator.EXECUTION_HINT_FIELD)) {
                 String executionHint = parser.text();
                 otherOptions.put(SamplerAggregator.EXECUTION_HINT_FIELD, executionHint);
                 return true;

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParser.java

@@ -19,7 +19,6 @@
 package org.elasticsearch.search.aggregations.bucket.significant;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.ParseFieldRegistry;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
@@ -33,6 +32,7 @@ import org.elasticsearch.search.aggregations.bucket.terms.AbstractTermsParser;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -81,17 +81,18 @@ public class SignificantTermsParser extends AbstractTermsParser {
     }
 
     @Override
-    public boolean parseSpecial(String aggregationName, XContentParser parser, ParseFieldMatcher parseFieldMatcher, Token token,
-            String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException {
+    public boolean parseSpecial(String aggregationName, XContentParseContext context, Token token,
+                                String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException {
         if (token == XContentParser.Token.START_OBJECT) {
             SignificanceHeuristicParser significanceHeuristicParser = significanceHeuristicParserRegistry
-                    .lookupReturningNullIfNotFound(currentFieldName, parseFieldMatcher);
+                    .lookupReturningNullIfNotFound(currentFieldName, context.getParseFieldMatcher());
             if (significanceHeuristicParser != null) {
-                SignificanceHeuristic significanceHeuristic = significanceHeuristicParser.parse(parser, parseFieldMatcher);
+                SignificanceHeuristic significanceHeuristic = significanceHeuristicParser.parse(context);
                 otherOptions.put(SignificantTermsAggregationBuilder.HEURISTIC, significanceHeuristic);
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, SignificantTermsAggregationBuilder.BACKGROUND_FILTER)) {
-                QueryParseContext queryParseContext = new QueryParseContext(queriesRegistry, parser, parseFieldMatcher);
+            } else if (context.matchField(currentFieldName, SignificantTermsAggregationBuilder.BACKGROUND_FILTER)) {
+                QueryParseContext queryParseContext = new QueryParseContext(context.getDefaultScriptLanguage(), queriesRegistry,
+                        context.getParser(), context.getParseFieldMatcher());
                 Optional<QueryBuilder> filter = queryParseContext.parseInnerQueryBuilder();
                 if (filter.isPresent()) {
                     otherOptions.put(SignificantTermsAggregationBuilder.BACKGROUND_FILTER, filter.get());

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/GND.java

@@ -22,12 +22,12 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
 import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 
 import java.io.IOException;
 
@@ -113,13 +113,13 @@ public class GND extends NXYSignificanceHeuristic {
         }
 
         @Override
-        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
-                throws IOException, QueryShardException {
+        public SignificanceHeuristic parse(XContentParseContext context) throws IOException, QueryShardException {
+            XContentParser parser = context.getParser();
             String givenName = parser.currentName();
             boolean backgroundIsSuperset = true;
             XContentParser.Token token = parser.nextToken();
             while (!token.equals(XContentParser.Token.END_OBJECT)) {
-                if (parseFieldMatcher.match(parser.currentName(), BACKGROUND_IS_SUPERSET)) {
+                if (context.matchField(parser.currentName(), BACKGROUND_IS_SUPERSET)) {
                     parser.nextToken();
                     backgroundIsSuperset = parser.booleanValue();
                 } else {

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/JLHScore.java

@@ -22,12 +22,12 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
 import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 
 import java.io.IOException;
 
@@ -104,8 +104,9 @@ public class JLHScore extends SignificanceHeuristic {
         return builder;
     }
 
-    public static SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
+    public static SignificanceHeuristic parse(XContentParseContext context)
             throws IOException, QueryShardException {
+        XContentParser parser = context.getParser();
         // move to the closing bracket
         if (!parser.nextToken().equals(XContentParser.Token.END_OBJECT)) {
             throw new ElasticsearchParseException(

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/NXYSignificanceHeuristic.java

@@ -23,12 +23,12 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 
 import java.io.IOException;
 
@@ -152,17 +152,18 @@ public abstract class NXYSignificanceHeuristic extends SignificanceHeuristic {
     public abstract static class NXYParser implements SignificanceHeuristicParser {
 
         @Override
-        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
+        public SignificanceHeuristic parse(XContentParseContext context)
                 throws IOException, QueryShardException {
+            XContentParser parser = context.getParser();
             String givenName = parser.currentName();
             boolean includeNegatives = false;
             boolean backgroundIsSuperset = true;
             XContentParser.Token token = parser.nextToken();
             while (!token.equals(XContentParser.Token.END_OBJECT)) {
-                if (parseFieldMatcher.match(parser.currentName(), INCLUDE_NEGATIVES_FIELD)) {
+                if (context.matchField(parser.currentName(), INCLUDE_NEGATIVES_FIELD)) {
                     parser.nextToken();
                     includeNegatives = parser.booleanValue();
-                } else if (parseFieldMatcher.match(parser.currentName(), BACKGROUND_IS_SUPERSET)) {
+                } else if (context.matchField(parser.currentName(), BACKGROUND_IS_SUPERSET)) {
                     parser.nextToken();
                     backgroundIsSuperset = parser.booleanValue();
                 } else {

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/PercentageScore.java

@@ -22,12 +22,12 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
 import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 
 import java.io.IOException;
 
@@ -56,8 +56,9 @@ public class PercentageScore extends SignificanceHeuristic {
         return builder;
     }
 
-    public static SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
+    public static SignificanceHeuristic parse(XContentParseContext context)
             throws IOException, QueryShardException {
+        XContentParser parser = context.getParser();
         // move to the closing bracket
         if (!parser.nextToken().equals(XContentParser.Token.END_OBJECT)) {
             throw new ElasticsearchParseException("failed to parse [percentage] significance heuristic. expected an empty object, but got [{}] instead", parser.currentToken());

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ScriptHeuristic.java

@@ -22,7 +22,6 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
 import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.logging.ESLoggerFactory;
@@ -35,6 +34,7 @@ import org.elasticsearch.script.Script.ScriptField;
 import org.elasticsearch.script.ScriptContext;
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.search.aggregations.InternalAggregation;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
@@ -146,8 +146,9 @@ public class ScriptHeuristic extends SignificanceHeuristic {
         return Objects.equals(script, other.script);
     }
 
-    public static SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
+    public static SignificanceHeuristic parse(XContentParseContext context)
             throws IOException, QueryShardException {
+        XContentParser parser = context.getParser();
         String heuristicName = parser.currentName();
         Script script = null;
         XContentParser.Token token;
@@ -156,8 +157,8 @@ public class ScriptHeuristic extends SignificanceHeuristic {
             if (token.equals(XContentParser.Token.FIELD_NAME)) {
                 currentFieldName = parser.currentName();
             } else {
-                if (parseFieldMatcher.match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, parseFieldMatcher);
+                if (context.matchField(currentFieldName, ScriptField.SCRIPT)) {
+                    script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else {
                     throw new ElasticsearchParseException("failed to parse [{}] significance heuristic. unknown object [{}]", heuristicName, currentFieldName);
                 }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicParser.java

@@ -20,9 +20,9 @@
 
 package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 
 import java.io.IOException;
 
@@ -31,6 +31,5 @@ import java.io.IOException;
  */
 @FunctionalInterface
 public interface SignificanceHeuristicParser {
-    SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher) throws IOException,
-            ParsingException;
+    SignificanceHeuristic parse(XContentParseContext context) throws IOException, ParsingException;
 }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractTermsParser.java

@@ -20,13 +20,13 @@
 package org.elasticsearch.search.aggregations.bucket.terms;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.AnyValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregationBuilder;
@@ -89,47 +89,48 @@ public abstract class AbstractTermsParser extends AnyValuesSourceParser {
                                                                                        Map<ParseField, Object> otherOptions);
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
-        if (incExcParser.token(currentFieldName, token, parser, parseFieldMatcher, otherOptions)) {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
+        if (incExcParser.token(currentFieldName, token, parser, context.getParseFieldMatcher(), otherOptions)) {
             return true;
         } else if (token == XContentParser.Token.VALUE_STRING) {
-            if (parseFieldMatcher.match(currentFieldName, EXECUTION_HINT_FIELD_NAME)) {
+            if (context.matchField(currentFieldName, EXECUTION_HINT_FIELD_NAME)) {
                 otherOptions.put(EXECUTION_HINT_FIELD_NAME, parser.text());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, SubAggCollectionMode.KEY)) {
-                otherOptions.put(SubAggCollectionMode.KEY, SubAggCollectionMode.parse(parser.text(), parseFieldMatcher));
+            } else if (context.matchField(currentFieldName, SubAggCollectionMode.KEY)) {
+                otherOptions.put(SubAggCollectionMode.KEY, SubAggCollectionMode.parse(parser.text(), context.getParseFieldMatcher()));
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
+            } else if (context.matchField(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
                 otherOptions.put(REQUIRED_SIZE_FIELD_NAME, parser.intValue());
                 return true;
-            } else if (parseSpecial(aggregationName, parser, parseFieldMatcher, token, currentFieldName, otherOptions)) {
+            } else if (parseSpecial(aggregationName, context, token, currentFieldName, otherOptions)) {
                 return true;
             }
         } else if (token == XContentParser.Token.VALUE_NUMBER) {
-            if (parseFieldMatcher.match(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
+            if (context.matchField(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
                 otherOptions.put(REQUIRED_SIZE_FIELD_NAME, parser.intValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, SHARD_SIZE_FIELD_NAME)) {
+            } else if (context.matchField(currentFieldName, SHARD_SIZE_FIELD_NAME)) {
                 otherOptions.put(SHARD_SIZE_FIELD_NAME, parser.intValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, MIN_DOC_COUNT_FIELD_NAME)) {
+            } else if (context.matchField(currentFieldName, MIN_DOC_COUNT_FIELD_NAME)) {
                 otherOptions.put(MIN_DOC_COUNT_FIELD_NAME, parser.longValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, SHARD_MIN_DOC_COUNT_FIELD_NAME)) {
+            } else if (context.matchField(currentFieldName, SHARD_MIN_DOC_COUNT_FIELD_NAME)) {
                 otherOptions.put(SHARD_MIN_DOC_COUNT_FIELD_NAME, parser.longValue());
                 return true;
-            } else if (parseSpecial(aggregationName, parser, parseFieldMatcher, token, currentFieldName, otherOptions)) {
+            } else if (parseSpecial(aggregationName, context, token, currentFieldName, otherOptions)) {
                 return true;
             }
-        } else if (parseSpecial(aggregationName, parser, parseFieldMatcher, token, currentFieldName, otherOptions)) {
+        } else if (parseSpecial(aggregationName, context, token, currentFieldName, otherOptions)) {
             return true;
         }
         return false;
     }
 
-    public abstract boolean parseSpecial(String aggregationName, XContentParser parser, ParseFieldMatcher parseFieldMatcher,
-            XContentParser.Token token, String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException;
+    public abstract boolean parseSpecial(String aggregationName, XContentParseContext context,
+                                         Token token, String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException;
 
     protected abstract TermsAggregator.BucketCountThresholds getDefaultBucketCountThresholds();
 

core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParser.java

@@ -19,7 +19,6 @@
 package org.elasticsearch.search.aggregations.bucket.terms;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
@@ -27,6 +26,7 @@ import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.elasticsearch.search.aggregations.bucket.terms.Terms.Order;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -75,15 +75,16 @@ public class TermsParser extends AbstractTermsParser {
     }
 
     @Override
-    public boolean parseSpecial(String aggregationName, XContentParser parser, ParseFieldMatcher parseFieldMatcher, Token token,
-            String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException {
+    public boolean parseSpecial(String aggregationName, XContentParseContext context, Token token,
+                                String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
         if (token == XContentParser.Token.START_OBJECT) {
-            if (parseFieldMatcher.match(currentFieldName, TermsAggregationBuilder.ORDER_FIELD)) {
+            if (context.matchField(currentFieldName, TermsAggregationBuilder.ORDER_FIELD)) {
                 otherOptions.put(TermsAggregationBuilder.ORDER_FIELD, Collections.singletonList(parseOrderParam(aggregationName, parser)));
                 return true;
             }
         } else if (token == XContentParser.Token.START_ARRAY) {
-            if (parseFieldMatcher.match(currentFieldName, TermsAggregationBuilder.ORDER_FIELD)) {
+            if (context.matchField(currentFieldName, TermsAggregationBuilder.ORDER_FIELD)) {
                 List<OrderElement> orderElements = new ArrayList<>();
                 while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
                     if (token == XContentParser.Token.START_OBJECT) {
@@ -98,7 +99,7 @@ public class TermsParser extends AbstractTermsParser {
                 return true;
             }
         } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
-            if (parseFieldMatcher.match(currentFieldName, TermsAggregationBuilder.SHOW_TERM_DOC_COUNT_ERROR)) {
+            if (context.matchField(currentFieldName, TermsAggregationBuilder.SHOW_TERM_DOC_COUNT_ERROR)) {
                 otherOptions.put(TermsAggregationBuilder.SHOW_TERM_DOC_COUNT_ERROR, parser.booleanValue());
                 return true;
             }

core/src/main/java/org/elasticsearch/search/aggregations/metrics/avg/AvgParser.java

@@ -19,9 +19,9 @@
 package org.elasticsearch.search.aggregations.metrics.avg;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -38,8 +38,8 @@ public class AvgParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/metrics/cardinality/CardinalityParser.java

@@ -20,10 +20,9 @@
 package org.elasticsearch.search.aggregations.metrics.cardinality;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
-import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.AnyValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -51,13 +50,13 @@ public class CardinalityParser extends AnyValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         if (token.isValue()) {
-            if (parseFieldMatcher.match(currentFieldName, CardinalityAggregationBuilder.PRECISION_THRESHOLD_FIELD)) {
-                otherOptions.put(CardinalityAggregationBuilder.PRECISION_THRESHOLD_FIELD, parser.longValue());
+            if (context.matchField(currentFieldName, CardinalityAggregationBuilder.PRECISION_THRESHOLD_FIELD)) {
+                otherOptions.put(CardinalityAggregationBuilder.PRECISION_THRESHOLD_FIELD, context.getParser().longValue());
                 return true;
-            } else if (parseFieldMatcher.match(currentFieldName, REHASH)) {
+            } else if (context.matchField(currentFieldName, REHASH)) {
                 // ignore
                 return true;
             }

core/src/main/java/org/elasticsearch/search/aggregations/metrics/geobounds/GeoBoundsParser.java

@@ -20,10 +20,10 @@
 package org.elasticsearch.search.aggregations.metrics.geobounds;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.GeoPointValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -48,11 +48,11 @@ public class GeoBoundsParser extends GeoPointValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         if (token == XContentParser.Token.VALUE_BOOLEAN) {
-            if (parseFieldMatcher.match(currentFieldName, GeoBoundsAggregator.WRAP_LONGITUDE_FIELD)) {
-                otherOptions.put(GeoBoundsAggregator.WRAP_LONGITUDE_FIELD, parser.booleanValue());
+            if (context.matchField(currentFieldName, GeoBoundsAggregator.WRAP_LONGITUDE_FIELD)) {
+                otherOptions.put(GeoBoundsAggregator.WRAP_LONGITUDE_FIELD, context.getParser().booleanValue());
                 return true;
             }
         }

core/src/main/java/org/elasticsearch/search/aggregations/metrics/geocentroid/GeoCentroidParser.java

@@ -20,10 +20,9 @@
 package org.elasticsearch.search.aggregations.metrics.geocentroid;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
-import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.GeoPointValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -40,8 +39,8 @@ public class GeoCentroidParser extends GeoPointValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/metrics/max/MaxParser.java

@@ -19,9 +19,9 @@
 package org.elasticsearch.search.aggregations.metrics.max;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -38,8 +38,8 @@ public class MaxParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/metrics/min/MinParser.java

@@ -19,10 +19,9 @@
 package org.elasticsearch.search.aggregations.metrics.min;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
-import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -39,8 +38,8 @@ public class MinParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/AbstractPercentilesParser.java

@@ -21,10 +21,10 @@ package org.elasticsearch.search.aggregations.metrics.percentiles;
 
 import com.carrotsearch.hppc.DoubleArrayList;
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSource.Numeric;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregationBuilder;
@@ -45,10 +45,11 @@ public abstract class AbstractPercentilesParser extends NumericValuesSourceParse
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        XContentParser parser = context.getParser();
         if (token == XContentParser.Token.START_ARRAY) {
-            if (parseFieldMatcher.match(currentFieldName, keysField())) {
+            if (context.matchField(currentFieldName, keysField())) {
                 DoubleArrayList values = new DoubleArrayList(10);
                 while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
                     double value = parser.doubleValue();
@@ -61,7 +62,7 @@ public abstract class AbstractPercentilesParser extends NumericValuesSourceParse
                 return false;
             }
         } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
-            if (parseFieldMatcher.match(currentFieldName, KEYED_FIELD)) {
+            if (context.matchField(currentFieldName, KEYED_FIELD)) {
                 boolean keyed = parser.booleanValue();
                 otherOptions.put(KEYED_FIELD, keyed);
                 return true;
@@ -80,7 +81,7 @@ public abstract class AbstractPercentilesParser extends NumericValuesSourceParse
                         if (token == XContentParser.Token.FIELD_NAME) {
                             currentFieldName = parser.currentName();
                         } else if (token == XContentParser.Token.VALUE_NUMBER) {
-                            if (parseFieldMatcher.match(currentFieldName, COMPRESSION_FIELD)) {
+                            if (context.matchField(currentFieldName, COMPRESSION_FIELD)) {
                                 double compression = parser.doubleValue();
                                 otherOptions.put(COMPRESSION_FIELD, compression);
                             } else {
@@ -96,7 +97,7 @@ public abstract class AbstractPercentilesParser extends NumericValuesSourceParse
                         if (token == XContentParser.Token.FIELD_NAME) {
                             currentFieldName = parser.currentName();
                         } else if (token == XContentParser.Token.VALUE_NUMBER) {
-                            if (parseFieldMatcher.match(currentFieldName, NUMBER_SIGNIFICANT_DIGITS_FIELD)) {
+                            if (context.matchField(currentFieldName, NUMBER_SIGNIFICANT_DIGITS_FIELD)) {
                                 int numberOfSignificantValueDigits = parser.intValue();
                                 otherOptions.put(NUMBER_SIGNIFICANT_DIGITS_FIELD, numberOfSignificantValueDigits);
                             } else {

core/src/main/java/org/elasticsearch/search/aggregations/metrics/scripted/ScriptedMetricAggregationBuilder.java

@@ -232,13 +232,13 @@ public class ScriptedMetricAggregationBuilder extends AbstractAggregationBuilder
                 currentFieldName = parser.currentName();
             } else if (token == XContentParser.Token.START_OBJECT || token == XContentParser.Token.VALUE_STRING) {
                 if (context.getParseFieldMatcher().match(currentFieldName, INIT_SCRIPT_FIELD)) {
-                    initScript = Script.parse(parser, context.getParseFieldMatcher());
+                    initScript = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else if (context.getParseFieldMatcher().match(currentFieldName, MAP_SCRIPT_FIELD)) {
-                    mapScript = Script.parse(parser, context.getParseFieldMatcher());
+                    mapScript = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else if (context.getParseFieldMatcher().match(currentFieldName, COMBINE_SCRIPT_FIELD)) {
-                    combineScript = Script.parse(parser, context.getParseFieldMatcher());
+                    combineScript = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else if (context.getParseFieldMatcher().match(currentFieldName, REDUCE_SCRIPT_FIELD)) {
-                    reduceScript = Script.parse(parser, context.getParseFieldMatcher());
+                    reduceScript = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else if (token == XContentParser.Token.START_OBJECT &&
                         context.getParseFieldMatcher().match(currentFieldName, PARAMS_FIELD)) {
                     params = parser.map();

core/src/main/java/org/elasticsearch/search/aggregations/metrics/stats/StatsParser.java

@@ -19,9 +19,9 @@
 package org.elasticsearch.search.aggregations.metrics.stats;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -38,8 +38,8 @@ public class StatsParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/metrics/stats/extended/ExtendedStatsParser.java

@@ -19,9 +19,9 @@
 package org.elasticsearch.search.aggregations.metrics.stats.extended;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -38,11 +38,11 @@ public class ExtendedStatsParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
-        if (parseFieldMatcher.match(currentFieldName, ExtendedStatsAggregator.SIGMA_FIELD)) {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
+        if (context.matchField(currentFieldName, ExtendedStatsAggregator.SIGMA_FIELD)) {
             if (token.isValue()) {
-                otherOptions.put(ExtendedStatsAggregator.SIGMA_FIELD, parser.doubleValue());
+                otherOptions.put(ExtendedStatsAggregator.SIGMA_FIELD, context.getParser().doubleValue());
                 return true;
             }
         }

core/src/main/java/org/elasticsearch/search/aggregations/metrics/sum/SumParser.java

@@ -19,9 +19,9 @@
 package org.elasticsearch.search.aggregations.metrics.sum;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.NumericValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -38,8 +38,8 @@ public class SumParser extends NumericValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/TopHitsAggregationBuilder.java

@@ -622,7 +622,7 @@ public class TopHitsAggregationBuilder extends AbstractAggregationBuilder<TopHit
                                     currentFieldName = parser.currentName();
                                 } else if (token.isValue()) {
                                     if (context.getParseFieldMatcher().match(currentFieldName, SearchSourceBuilder.SCRIPT_FIELD)) {
-                                        script = Script.parse(parser, context.getParseFieldMatcher());
+                                        script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                                     } else if (context.getParseFieldMatcher().match(currentFieldName,
                                             SearchSourceBuilder.IGNORE_FAILURE_FIELD)) {
                                         ignoreFailure = parser.booleanValue();
@@ -633,7 +633,7 @@ public class TopHitsAggregationBuilder extends AbstractAggregationBuilder<TopHit
                                     }
                                 } else if (token == XContentParser.Token.START_OBJECT) {
                                     if (context.getParseFieldMatcher().match(currentFieldName, SearchSourceBuilder.SCRIPT_FIELD)) {
-                                        script = Script.parse(parser, context.getParseFieldMatcher());
+                                        script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                                     } else {
                                         throw new ParsingException(parser.getTokenLocation(),
                                                 "Unknown key for a " + token + " in [" + currentFieldName + "].",

core/src/main/java/org/elasticsearch/search/aggregations/metrics/valuecount/ValueCountParser.java

@@ -19,9 +19,9 @@
 package org.elasticsearch.search.aggregations.metrics.valuecount;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.AnyValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregationBuilder;
@@ -40,8 +40,8 @@ public class ValueCountParser extends AnyValuesSourceParser {
     }
 
     @Override
-    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+    protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                            XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException {
         return false;
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/pipeline/bucketscript/BucketScriptPipelineAggregationBuilder.java

@@ -179,7 +179,7 @@ public class BucketScriptPipelineAggregationBuilder extends AbstractPipelineAggr
                 } else if (context.getParseFieldMatcher().match(currentFieldName, GAP_POLICY)) {
                     gapPolicy = GapPolicy.parse(context, parser.text(), parser.getTokenLocation());
                 } else if (context.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, context.getParseFieldMatcher());
+                    script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else {
                     throw new ParsingException(parser.getTokenLocation(),
                             "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
@@ -201,7 +201,7 @@ public class BucketScriptPipelineAggregationBuilder extends AbstractPipelineAggr
                 }
             } else if (token == XContentParser.Token.START_OBJECT) {
                 if (context.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, context.getParseFieldMatcher());
+                    script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
                     Map<String, Object> map = parser.map();
                     bucketsPathsMap = new HashMap<>();
@@ -260,4 +260,4 @@ public class BucketScriptPipelineAggregationBuilder extends AbstractPipelineAggr
     public String getWriteableName() {
         return NAME;
     }
-}
+}

core/src/main/java/org/elasticsearch/search/aggregations/pipeline/bucketselector/BucketSelectorPipelineAggregationBuilder.java

@@ -142,7 +142,7 @@ public class BucketSelectorPipelineAggregationBuilder extends AbstractPipelineAg
                 } else if (context.getParseFieldMatcher().match(currentFieldName, GAP_POLICY)) {
                     gapPolicy = GapPolicy.parse(context, parser.text(), parser.getTokenLocation());
                 } else if (context.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, context.getParseFieldMatcher());
+                    script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else {
                     throw new ParsingException(parser.getTokenLocation(),
                             "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
@@ -164,7 +164,7 @@ public class BucketSelectorPipelineAggregationBuilder extends AbstractPipelineAg
                 }
             } else if (token == XContentParser.Token.START_OBJECT) {
                 if (context.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, context.getParseFieldMatcher());
+                    script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                 } else if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
                     Map<String, Object> map = parser.map();
                     bucketsPathsMap = new HashMap<>();
@@ -219,4 +219,4 @@ public class BucketSelectorPipelineAggregationBuilder extends AbstractPipelineAg
     public String getWriteableName() {
         return NAME;
     }
-}
+}

core/src/main/java/org/elasticsearch/search/aggregations/support/AbstractValuesSourceParser.java

@@ -20,7 +20,6 @@
 package org.elasticsearch.search.aggregations.support;
 
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryParseContext;
@@ -95,6 +94,8 @@ public abstract class AbstractValuesSourceParser<VS extends ValuesSource>
         Object missing = null;
         DateTimeZone timezone = null;
         Map<ParseField, Object> otherOptions = new HashMap<>();
+        XContentParseContext parserContext =
+                new XContentParseContext(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
 
         XContentParser.Token token;
         String currentFieldName = null;
@@ -126,22 +127,22 @@ public abstract class AbstractValuesSourceParser<VS extends ValuesSource>
                                             + valueType + "]. It can only work on value of type ["
                                             + targetValueType + "]");
                         }
-                    } else if (!token(aggregationName, currentFieldName, token, parser, context.getParseFieldMatcher(), otherOptions)) {
+                    } else if (!token(aggregationName, currentFieldName, token, parserContext, otherOptions)) {
                         throw new ParsingException(parser.getTokenLocation(),
                                 "Unexpected token " + token + " [" + currentFieldName + "] in [" + aggregationName + "].");
                     }
-                } else if (!token(aggregationName, currentFieldName, token, parser, context.getParseFieldMatcher(), otherOptions)) {
+                } else if (!token(aggregationName, currentFieldName, token, parserContext, otherOptions)) {
                     throw new ParsingException(parser.getTokenLocation(),
                             "Unexpected token " + token + " [" + currentFieldName + "] in [" + aggregationName + "].");
                 }
             } else if (scriptable && token == XContentParser.Token.START_OBJECT) {
                 if (context.getParseFieldMatcher().match(currentFieldName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, context.getParseFieldMatcher());
-                } else if (!token(aggregationName, currentFieldName, token, parser, context.getParseFieldMatcher(), otherOptions)) {
+                    script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
+                } else if (!token(aggregationName, currentFieldName, token, parserContext, otherOptions)) {
                     throw new ParsingException(parser.getTokenLocation(),
                             "Unexpected token " + token + " [" + currentFieldName + "] in [" + aggregationName + "].");
                 }
-            } else if (!token(aggregationName, currentFieldName, token, parser, context.getParseFieldMatcher(), otherOptions)) {
+            } else if (!token(aggregationName, currentFieldName, token, parserContext, otherOptions)) {
                 throw new ParsingException(parser.getTokenLocation(),
                         "Unexpected token " + token + " [" + currentFieldName + "] in [" + aggregationName + "].");
             }
@@ -184,8 +185,7 @@ public abstract class AbstractValuesSourceParser<VS extends ValuesSource>
      *            the target type of the final value output by the aggregation
      * @param otherOptions
      *            a {@link Map} containing the extra options parsed by the
-     *            {@link #token(String, String, org.elasticsearch.common.xcontent.XContentParser.Token,
-     *             XContentParser, ParseFieldMatcher, Map)}
+     *            {@link #token(String, String, XContentParser.Token, XContentParseContext, Map)}
      *            method
      * @return the created factory
      */
@@ -203,10 +203,8 @@ public abstract class AbstractValuesSourceParser<VS extends ValuesSource>
      *            the name of the current field being parsed
      * @param token
      *            the current token for the parser
-     * @param parser
-     *            the parser
-     * @param parseFieldMatcher
-     *            the {@link ParseFieldMatcher} to use to match field names
+     * @param context
+     *            the query context
      * @param otherOptions
      *            a {@link Map} of options to be populated by successive calls
      *            to this method which will then be passed to the
@@ -217,6 +215,6 @@ public abstract class AbstractValuesSourceParser<VS extends ValuesSource>
      * @throws IOException
      *             if an error occurs whilst parsing
      */
-    protected abstract boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
-            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException;
+    protected abstract boolean token(String aggregationName, String currentFieldName, XContentParser.Token token,
+                                     XContentParseContext context, Map<ParseField, Object> otherOptions) throws IOException;
 }

core/src/main/java/org/elasticsearch/search/aggregations/support/XContentParseContext.java

@@ -0,0 +1,65 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.search.aggregations.support;
+
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.xcontent.XContentParser;
+
+/**
+ * A minimal context for parsing xcontent into aggregation builders.
+ * Only a minimal set of dependencies and settings are available.
+ */
+public final class XContentParseContext {
+
+    private final XContentParser parser;
+
+    private final ParseFieldMatcher parseFieldMatcher;
+
+    private final String defaultScriptLanguage;
+
+    public XContentParseContext(XContentParser parser, ParseFieldMatcher parseFieldMatcher, String defaultScriptLanguage) {
+        this.parser = parser;
+        this.parseFieldMatcher = parseFieldMatcher;
+        this.defaultScriptLanguage = defaultScriptLanguage;
+    }
+
+    public XContentParser getParser() {
+        return parser;
+    }
+
+    public ParseFieldMatcher getParseFieldMatcher() {
+        return parseFieldMatcher;
+    }
+
+    public String getDefaultScriptLanguage() {
+        return defaultScriptLanguage;
+    }
+
+    /**
+     * Returns whether the parse field we're looking for matches with the found field name.
+     *
+     * Helper that delegates to {@link ParseFieldMatcher#match(String, ParseField)}.
+     */
+    public boolean matchField(String fieldName, ParseField parseField) {
+        return parseFieldMatcher.match(fieldName, parseField);
+    }
+
+}

core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java

@@ -1273,7 +1273,7 @@ public final class SearchSourceBuilder extends ToXContentToBytes implements Writ
                         currentFieldName = parser.currentName();
                     } else if (token.isValue()) {
                         if (context.getParseFieldMatcher().match(currentFieldName, SCRIPT_FIELD)) {
-                            script = Script.parse(parser, context.getParseFieldMatcher());
+                            script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                         } else if (context.getParseFieldMatcher().match(currentFieldName, IGNORE_FAILURE_FIELD)) {
                             ignoreFailure = parser.booleanValue();
                         } else {
@@ -1282,7 +1282,7 @@ public final class SearchSourceBuilder extends ToXContentToBytes implements Writ
                         }
                     } else if (token == XContentParser.Token.START_OBJECT) {
                         if (context.getParseFieldMatcher().match(currentFieldName, SCRIPT_FIELD)) {
-                            script = Script.parse(parser, context.getParseFieldMatcher());
+                            script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
                         } else {
                             throw new ParsingException(parser.getTokenLocation(), "Unknown key for a " + token + " in [" + currentFieldName
                                     + "].", parser.getTokenLocation());

core/src/main/java/org/elasticsearch/search/sort/ScriptSortBuilder.java

@@ -244,7 +244,7 @@ public class ScriptSortBuilder extends SortBuilder<ScriptSortBuilder> {
                 currentName = parser.currentName();
             } else if (token == XContentParser.Token.START_OBJECT) {
                 if (parseField.match(currentName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, parseField);
+                    script = Script.parse(parser, parseField, context.getDefaultScriptLanguage());
                 } else if (parseField.match(currentName, NESTED_FILTER_FIELD)) {
                     nestedFilter = context.parseInnerQueryBuilder();
                 } else {
@@ -260,7 +260,7 @@ public class ScriptSortBuilder extends SortBuilder<ScriptSortBuilder> {
                 } else if (parseField.match(currentName, NESTED_PATH_FIELD)) {
                     nestedPath = parser.text();
                 } else if (parseField.match(currentName, ScriptField.SCRIPT)) {
-                    script = Script.parse(parser, parseField);
+                    script = Script.parse(parser, parseField, context.getDefaultScriptLanguage());
                 } else {
                     throw new ParsingException(parser.getTokenLocation(), "[" + NAME + "] failed to parse field [" + currentName + "]");
                 }

core/src/test/java/org/elasticsearch/action/bulk/BulkWithUpdatesIT.java

@@ -60,14 +60,6 @@ import static org.hamcrest.Matchers.nullValue;
 
 public class BulkWithUpdatesIT extends ESIntegTestCase {
 
-    @Override
-    protected Settings nodeSettings(int nodeOrdinal) {
-        return Settings.builder()
-                .put(super.nodeSettings(nodeOrdinal))
-                .put("script.default_lang", CustomScriptPlugin.NAME)
-                .build();
-    }
-
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Collections.singleton(CustomScriptPlugin.class);
@@ -557,6 +549,7 @@ public class BulkWithUpdatesIT extends ESIntegTestCase {
                 "  \"script\" : {" +
                 "    \"inline\" : \"ctx._source.field2 = 'value2'\"" +
                 "  }," +
+                "  \"lang\" : \"" + CustomScriptPlugin.NAME + "\"," +
                 "  \"upsert\" : {" +
                 "    \"field1\" : \"value1'\"" +
                 "  }" +
@@ -589,7 +582,9 @@ public class BulkWithUpdatesIT extends ESIntegTestCase {
         assertThat(bulkResponse.getItems().length, equalTo(3));
         assertThat(bulkResponse.getItems()[0].isFailed(), equalTo(false));
         assertThat(bulkResponse.getItems()[1].isFailed(), equalTo(false));
-        assertThat(bulkResponse.getItems()[2].isFailed(), equalTo(false));
+        assertThat(bulkResponse.getItems()[2].isFailed(), equalTo(true));
+        assertThat(bulkResponse.getItems()[2].getFailure().getCause().getCause().getMessage(),
+                equalTo("script_lang not supported [painless]"));
 
         client().admin().indices().prepareRefresh("test").get();
 

core/src/test/java/org/elasticsearch/action/update/UpdateRequestTests.java

@@ -55,7 +55,7 @@ public class UpdateRequestTests extends ESTestCase {
         assertThat(script, notNullValue());
         assertThat(script.getScript(), equalTo("script1"));
         assertThat(script.getType(), equalTo(ScriptType.INLINE));
-        assertThat(script.getLang(), nullValue());
+        assertThat(script.getLang(), equalTo(Script.DEFAULT_SCRIPT_LANG));
         Map<String, Object> params = script.getParams();
         assertThat(params, nullValue());
 
@@ -67,7 +67,7 @@ public class UpdateRequestTests extends ESTestCase {
         assertThat(script, notNullValue());
         assertThat(script.getScript(), equalTo("script1"));
         assertThat(script.getType(), equalTo(ScriptType.INLINE));
-        assertThat(script.getLang(), nullValue());
+        assertThat(script.getLang(), equalTo(Script.DEFAULT_SCRIPT_LANG));
         params = script.getParams();
         assertThat(params, nullValue());
 
@@ -79,7 +79,7 @@ public class UpdateRequestTests extends ESTestCase {
         assertThat(script, notNullValue());
         assertThat(script.getScript(), equalTo("script1"));
         assertThat(script.getType(), equalTo(ScriptType.INLINE));
-        assertThat(script.getLang(), nullValue());
+        assertThat(script.getLang(), equalTo(Script.DEFAULT_SCRIPT_LANG));
         params = script.getParams();
         assertThat(params, notNullValue());
         assertThat(params.size(), equalTo(1));
@@ -92,7 +92,7 @@ public class UpdateRequestTests extends ESTestCase {
         assertThat(script, notNullValue());
         assertThat(script.getScript(), equalTo("script1"));
         assertThat(script.getType(), equalTo(ScriptType.INLINE));
-        assertThat(script.getLang(), nullValue());
+        assertThat(script.getLang(), equalTo(Script.DEFAULT_SCRIPT_LANG));
         params = script.getParams();
         assertThat(params, notNullValue());
         assertThat(params.size(), equalTo(1));
@@ -107,7 +107,7 @@ public class UpdateRequestTests extends ESTestCase {
         assertThat(script, notNullValue());
         assertThat(script.getScript(), equalTo("script1"));
         assertThat(script.getType(), equalTo(ScriptType.INLINE));
-        assertThat(script.getLang(), nullValue());
+        assertThat(script.getLang(), equalTo(Script.DEFAULT_SCRIPT_LANG));
         params = script.getParams();
         assertThat(params, notNullValue());
         assertThat(params.size(), equalTo(1));
@@ -124,7 +124,7 @@ public class UpdateRequestTests extends ESTestCase {
         assertThat(script, notNullValue());
         assertThat(script.getScript(), equalTo("script1"));
         assertThat(script.getType(), equalTo(ScriptType.INLINE));
-        assertThat(script.getLang(), nullValue());
+        assertThat(script.getLang(), equalTo(Script.DEFAULT_SCRIPT_LANG));
         params = script.getParams();
         assertThat(params, notNullValue());
         assertThat(params.size(), equalTo(1));

core/src/test/java/org/elasticsearch/index/query/QueryRewriteContextTests.java

@@ -0,0 +1,63 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.index.query;
+
+import org.elasticsearch.Version;
+import org.elasticsearch.cluster.metadata.IndexMetaData;
+import org.elasticsearch.common.bytes.BytesArray;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.XContentHelper;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.index.IndexSettings;
+import org.elasticsearch.indices.query.IndicesQueriesRegistry;
+import org.elasticsearch.script.ScriptSettings;
+import org.elasticsearch.search.SearchModule;
+import org.elasticsearch.test.ESTestCase;
+
+import static java.util.Collections.emptyList;
+
+public class QueryRewriteContextTests extends ESTestCase {
+
+    public void testNewParseContextWithLegacyScriptLanguage() throws Exception {
+        String defaultLegacyScriptLanguage = randomAsciiOfLength(4);
+        IndexMetaData.Builder indexMetadata = new IndexMetaData.Builder("index");
+        indexMetadata.settings(Settings.builder().put("index.version.created", Version.CURRENT)
+                .put("index.number_of_shards", 1)
+                .put("index.number_of_replicas", 1)
+        );
+        IndicesQueriesRegistry indicesQueriesRegistry = new SearchModule(Settings.EMPTY, false, emptyList()).getQueryParserRegistry();
+        IndexSettings indexSettings = new IndexSettings(indexMetadata.build(),
+                Settings.builder().put(ScriptSettings.LEGACY_SCRIPT_SETTING, defaultLegacyScriptLanguage).build());
+        QueryRewriteContext queryRewriteContext =
+                new QueryRewriteContext(indexSettings, null, null, indicesQueriesRegistry, null, null, null);;
+
+        // verify that the default script language in the query parse context is equal to defaultLegacyScriptLanguage variable:
+        QueryParseContext queryParseContext =
+                queryRewriteContext.newParseContextWithLegacyScriptLanguage(XContentHelper.createParser(new BytesArray("{}")));
+        assertEquals(defaultLegacyScriptLanguage, queryParseContext.getDefaultScriptLanguage());
+
+        // verify that the script query's script language is equal to defaultLegacyScriptLanguage variable:
+        XContentParser parser = XContentHelper.createParser(new BytesArray("{\"script\" : {\"script\": \"return true\"}}"));
+        queryParseContext = queryRewriteContext.newParseContextWithLegacyScriptLanguage(parser);
+        ScriptQueryBuilder queryBuilder = (ScriptQueryBuilder) queryParseContext.parseInnerQueryBuilder().get();
+        assertEquals(defaultLegacyScriptLanguage, queryBuilder.script().getLang());
+    }
+
+}

core/src/test/java/org/elasticsearch/script/ScriptServiceTests.java

@@ -45,6 +45,7 @@ import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 
 import static org.hamcrest.CoreMatchers.containsString;
@@ -86,7 +87,9 @@ public class ScriptServiceTests extends ESTestCase {
         resourceWatcherService = new ResourceWatcherService(baseSettings, null);
         scriptEngineService = new TestEngineService();
         dangerousScriptEngineService = new TestDangerousEngineService();
-        scriptEnginesByLangMap = ScriptModesTests.buildScriptEnginesByLangMap(Collections.singleton(scriptEngineService));
+        TestEngineService defaultScriptServiceEngine = new TestEngineService(Script.DEFAULT_SCRIPT_LANG) {};
+        scriptEnginesByLangMap = ScriptModesTests.buildScriptEnginesByLangMap(
+                new HashSet<>(Arrays.asList(scriptEngineService, defaultScriptServiceEngine)));
         //randomly register custom script contexts
         int randomInt = randomIntBetween(0, 3);
         //prevent duplicates using map
@@ -103,7 +106,8 @@ public class ScriptServiceTests extends ESTestCase {
             String context = plugin + "_" + operation;
             contexts.put(context, new ScriptContext.Plugin(plugin, operation));
         }
-        scriptEngineRegistry = new ScriptEngineRegistry(Arrays.asList(scriptEngineService, dangerousScriptEngineService));
+        scriptEngineRegistry = new ScriptEngineRegistry(Arrays.asList(scriptEngineService, dangerousScriptEngineService,
+                defaultScriptServiceEngine));
         scriptContextRegistry = new ScriptContextRegistry(contexts.values());
         scriptSettings = new ScriptSettings(scriptEngineRegistry, scriptContextRegistry);
         scriptContexts = scriptContextRegistry.scriptContexts().toArray(new ScriptContext[scriptContextRegistry.scriptContexts().size()]);
@@ -406,12 +410,11 @@ public class ScriptServiceTests extends ESTestCase {
 
     public void testDefaultLanguage() throws IOException {
         Settings.Builder builder = Settings.builder();
-        builder.put("script.default_lang", "test");
         builder.put("script.inline", "true");
         buildScriptService(builder.build());
         CompiledScript script = scriptService.compile(new Script("1 + 1", ScriptType.INLINE, null, null),
                 randomFrom(scriptContexts), Collections.emptyMap());
-        assertEquals(script.lang(), "test");
+        assertEquals(script.lang(), Script.DEFAULT_SCRIPT_LANG);
     }
 
     public void testStoreScript() throws Exception {
@@ -509,14 +512,24 @@ public class ScriptServiceTests extends ESTestCase {
 
         public static final String NAME = "test";
 
+        private final String name;
+
+        public TestEngineService() {
+            this(NAME);
+        }
+
+        public TestEngineService(String name) {
+            this.name = name;
+        }
+
         @Override
         public String getType() {
-            return NAME;
+            return name;
         }
 
         @Override
         public String getExtension() {
-            return NAME;
+            return name;
         }
 
         @Override

core/src/test/java/org/elasticsearch/script/ScriptSettingsTests.java

@@ -34,32 +34,33 @@ import static org.hamcrest.Matchers.equalTo;
 
 public class ScriptSettingsTests extends ESTestCase {
 
-    public void testDefaultLanguageIsPainless() {
+    public void testDefaultLegacyLanguageIsPainless() {
         ScriptEngineRegistry scriptEngineRegistry =
                 new ScriptEngineRegistry(Collections.singletonList(new CustomScriptEngineService()));
         ScriptContextRegistry scriptContextRegistry = new ScriptContextRegistry(Collections.emptyList());
         ScriptSettings scriptSettings = new ScriptSettings(scriptEngineRegistry, scriptContextRegistry);
-        assertThat(scriptSettings.getDefaultScriptLanguageSetting().get(Settings.EMPTY), equalTo("painless"));
+        assertThat(scriptSettings.getDefaultLegacyScriptLanguageSetting().get(Settings.EMPTY),
+                equalTo(ScriptSettings.LEGACY_DEFAULT_LANG));
     }
 
-    public void testCustomDefaultLanguage() {
+    public void testCustomLegacyDefaultLanguage() {
         ScriptEngineRegistry scriptEngineRegistry =
             new ScriptEngineRegistry(Collections.singletonList(new CustomScriptEngineService()));
         ScriptContextRegistry scriptContextRegistry = new ScriptContextRegistry(Collections.emptyList());
         ScriptSettings scriptSettings = new ScriptSettings(scriptEngineRegistry, scriptContextRegistry);
         String defaultLanguage = CustomScriptEngineService.NAME;
-        Settings settings = Settings.builder().put("script.default_lang", defaultLanguage).build();
-        assertThat(scriptSettings.getDefaultScriptLanguageSetting().get(settings), equalTo(defaultLanguage));
+        Settings settings = Settings.builder().put(ScriptSettings.LEGACY_SCRIPT_SETTING, defaultLanguage).build();
+        assertThat(scriptSettings.getDefaultLegacyScriptLanguageSetting().get(settings), equalTo(defaultLanguage));
     }
 
-    public void testInvalidDefaultLanguage() {
+    public void testInvalidLegacyDefaultLanguage() {
         ScriptEngineRegistry scriptEngineRegistry =
             new ScriptEngineRegistry(Collections.singletonList(new CustomScriptEngineService()));
         ScriptContextRegistry scriptContextRegistry = new ScriptContextRegistry(Collections.emptyList());
         ScriptSettings scriptSettings = new ScriptSettings(scriptEngineRegistry, scriptContextRegistry);
-        Settings settings = Settings.builder().put("script.default_lang", "C++").build();
+        Settings settings = Settings.builder().put(ScriptSettings.LEGACY_SCRIPT_SETTING, "C++").build();
         try {
-            scriptSettings.getDefaultScriptLanguageSetting().get(settings);
+            scriptSettings.getDefaultLegacyScriptLanguageSetting().get(settings);
             fail("should have seen unregistered default language");
         } catch (IllegalArgumentException e) {
             assertThat(e.getMessage(), containsString("unregistered default language [C++]"));

core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java

@@ -20,12 +20,10 @@ package org.elasticsearch.search.aggregations.bucket;
 
 import org.elasticsearch.action.index.IndexRequestBuilder;
 import org.elasticsearch.action.search.SearchResponse;
-import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
-import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryBuilders;
 import org.elasticsearch.index.query.QueryShardException;
 import org.elasticsearch.plugins.Plugin;
@@ -49,6 +47,7 @@ import org.elasticsearch.search.aggregations.bucket.significant.heuristics.Signi
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicParser;
 import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
 import org.elasticsearch.search.aggregations.bucket.terms.Terms;
+import org.elasticsearch.search.aggregations.support.XContentParseContext;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.search.aggregations.bucket.SharedSignificantTermsTestMethods;
 
@@ -172,7 +171,7 @@ public class SignificantTermsSignificanceScoreIT extends ESIntegTestCase {
         @Override
         public List<SearchExtensionSpec<SignificanceHeuristic, SignificanceHeuristicParser>> getSignificanceHeuristics() {
             return singletonList(new SearchExtensionSpec<SignificanceHeuristic, SignificanceHeuristicParser>(SimpleHeuristic.NAME,
-                    SimpleHeuristic::new, SimpleHeuristic::parse));
+                    SimpleHeuristic::new, (context) -> SimpleHeuristic.parse(context)));
         }
 
         @Override
@@ -239,9 +238,9 @@ public class SignificantTermsSignificanceScoreIT extends ESIntegTestCase {
             return subsetFreq / subsetSize > supersetFreq / supersetSize ? 2.0 : 1.0;
         }
 
-        public static SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
+        public static SignificanceHeuristic parse(XContentParseContext context)
                 throws IOException, QueryShardException {
-            parser.nextToken();
+            context.getParser().nextToken();
             return new SimpleHeuristic();
         }
     }

core/src/test/java/org/elasticsearch/search/sort/ScriptSortBuilderTests.java

@@ -182,7 +182,7 @@ public class ScriptSortBuilderTests extends AbstractSortTestCase<ScriptSortBuild
         QueryParseContext context = new QueryParseContext(indicesQueriesRegistry, parser, ParseFieldMatcher.STRICT);
         ScriptSortBuilder builder = ScriptSortBuilder.fromXContent(context, null);
         assertEquals("doc['field_name'].value * factor", builder.script().getScript());
-        assertNull(builder.script().getLang());
+        assertEquals(Script.DEFAULT_SCRIPT_LANG, builder.script().getLang());
         assertEquals(1.1, builder.script().getParams().get("factor"));
         assertEquals(ScriptType.INLINE, builder.script().getType());
         assertEquals(ScriptSortType.NUMBER, builder.type());
@@ -208,7 +208,7 @@ public class ScriptSortBuilderTests extends AbstractSortTestCase<ScriptSortBuild
         QueryParseContext context = new QueryParseContext(indicesQueriesRegistry, parser, ParseFieldMatcher.STRICT);
         ScriptSortBuilder builder = ScriptSortBuilder.fromXContent(context, null);
         assertEquals("doc['field_name'].value", builder.script().getScript());
-        assertNull(builder.script().getLang());
+        assertEquals(Script.DEFAULT_SCRIPT_LANG, builder.script().getLang());
         assertNull(builder.script().getParams());
         assertEquals(ScriptType.INLINE, builder.script().getType());
         assertEquals(ScriptSortType.NUMBER, builder.type());

docs/reference/migration/migrate_5_0/percolator.asciidoc

@@ -24,6 +24,10 @@ Instead a <<percolator,percolator field type>> must be configured prior to index
 Indices with a `.percolator` type created on a version before 5.0.0 can still be used,
 but new indices no longer accept the `.percolator` type.
 
+However it is strongly recommended to reindex any indices containing percolator queries created prior
+upgrading to Elasticsearch 5. By doing this the `percolate` query utilize the extracted terms the `percolator`
+field type extracted from the percolator queries and potentially execute many times faster.
+
 ==== Percolate document mapping
 
 The `percolate` query no longer modifies the mappings. Before the percolate API
@@ -53,6 +57,22 @@ The percolate stats have been removed. This is because the percolator no longer
 The percolator no longer accepts percolator queries containing `range` queries with ranges that are based on current
 time (using `now`).
 
+==== Percolator queries containing scripts.
+
+Percolator queries that contain scripts (For example: `script` query or a `function_score` query script function) that
+have no explicit language specified will use the Painless scripting language from version 5.0 and up.
+
+Scripts with no explicit language set in percolator queries stored in indices created prior to version 5.0
+will use the language that has been configured in the `script.legacy.default_lang` setting. This setting defaults to
+the Groovy scripting language, which was the default for versions prior to 5.0. If your default scripting language was
+different then set the `script.legacy.default_lang` setting to the language you used before.
+
+In order to make use of the new `percolator` field type all percolator queries should be reindexed into a new index.
+When reindexing percolator queries with scripts that have no explicit language defined into a new index, one of the
+following two things should be done in order to make the scripts work:
+* (Recommended approach) While reindexing the percolator documents, migrate the scripts to the Painless scripting language.
+* or add `lang` parameter on the script and set it the language these scripts were written in.
+
 ==== Java client
 
 The percolator is no longer part of the core elasticsearch dependency. It has moved to the percolator module.

docs/reference/migration/migrate_5_0/scripting.asciidoc

@@ -9,8 +9,6 @@ to help make the transition between languages as simple as possible.
 
 Documentation for Painless can be found at <<modules-scripting-painless,Painless Scripting Language>>
 
-It is also possible to set the default language back to Groovy using the following setting: `script.default_lang: groovy`
-
 One common difference to note between Groovy and Painless is the use of parameters -- all parameters in Painless
 must be prefixed with `params.` now.  The following example shows the difference:
 
@@ -48,6 +46,12 @@ Painless (`my_modifer` is prefixed with `params`):
 }
 -----------------------------------
 
+The `script.default_lang` setting has been removed. It is no longer possible set the default scripting language. If a
+different language than `painless` is used then this should be explicitly specified on the script itself.
+
+For scripts with no explicit language defined, that are part of already stored percolator queries, the default language
+can be controlled with the `script.legacy.default_lang` setting.
+
 ==== Removed 1.x script and template syntax
 
 The deprecated 1.x syntax of defining inline scripts / templates and referring to file or index base scripts / templates

modules/percolator/src/main/java/org/elasticsearch/percolator/PercolateQueryBuilder.java

@@ -515,7 +515,8 @@ public class PercolateQueryBuilder extends AbstractQueryBuilder<PercolateQueryBu
                             currentFieldName = sourceParser.currentName();
                         } else if (token == XContentParser.Token.START_OBJECT) {
                             if ("query".equals(currentFieldName)) {
-                                return parseQuery(context, mapUnmappedFieldsAsString, sourceParser);
+                                QueryParseContext queryParseContext = context.newParseContextWithLegacyScriptLanguage(sourceParser);
+                                return parseQuery(context, mapUnmappedFieldsAsString, queryParseContext, sourceParser);
                             } else {
                                 sourceParser.skipChildren();
                             }

modules/percolator/src/main/java/org/elasticsearch/percolator/PercolatorFieldMapper.java

@@ -270,7 +270,9 @@ public class PercolatorFieldMapper extends FieldMapper {
         }
 
         XContentParser parser = context.parser();
-        QueryBuilder queryBuilder = parseQueryBuilder(queryShardContext.newParseContext(parser), parser.getTokenLocation());
+        QueryBuilder queryBuilder = parseQueryBuilder(
+                queryShardContext.newParseContext(parser), parser.getTokenLocation()
+        );
         verifyQuery(queryBuilder);
         // Fetching of terms, shapes and indexed scripts happen during this rewrite:
         queryBuilder = queryBuilder.rewrite(queryShardContext);
@@ -312,7 +314,12 @@ public class PercolatorFieldMapper extends FieldMapper {
     }
 
     public static Query parseQuery(QueryShardContext context, boolean mapUnmappedFieldsAsString, XContentParser parser) throws IOException {
-        return toQuery(context, mapUnmappedFieldsAsString, parseQueryBuilder(context.newParseContext(parser), parser.getTokenLocation()));
+        return parseQuery(context, mapUnmappedFieldsAsString, context.newParseContext(parser), parser);
+    }
+
+    public static Query parseQuery(QueryShardContext context, boolean mapUnmappedFieldsAsString, QueryParseContext queryParseContext,
+                                   XContentParser parser) throws IOException {
+        return toQuery(context, mapUnmappedFieldsAsString, parseQueryBuilder(queryParseContext, parser.getTokenLocation()));
     }
 
     static Query toQuery(QueryShardContext context, boolean mapUnmappedFieldsAsString, QueryBuilder queryBuilder) throws IOException {

modules/percolator/src/test/java/org/elasticsearch/percolator/PercolatorBackwardsCompatibilityTests.java

@@ -21,6 +21,7 @@ package org.elasticsearch.percolator;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util.TestUtil;
 import org.elasticsearch.Version;
+import org.elasticsearch.action.get.GetResponse;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.MappingMetaData;
@@ -28,20 +29,26 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.support.XContentMapValues;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.script.MockScriptPlugin;
 import org.elasticsearch.search.sort.SortOrder;
 import org.elasticsearch.test.ESIntegTestCase;
 
 import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Map;
+import java.util.function.Function;
 
 import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.elasticsearch.index.query.QueryBuilders.matchQuery;
+import static org.elasticsearch.index.query.QueryBuilders.scriptQuery;
 import static org.elasticsearch.percolator.PercolatorTestUtil.preparePercolate;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.notNullValue;
+import static org.hamcrest.Matchers.nullValue;
 
 @ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0, numClientNodes = 0)
 @LuceneTestCase.SuppressFileSystems("ExtrasFS")
@@ -52,7 +59,7 @@ public class PercolatorBackwardsCompatibilityTests extends ESIntegTestCase {
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Collections.singleton(PercolatorPlugin.class);
+        return Arrays.asList(PercolatorPlugin.class, FoolMeScriptLang.class);
     }
 
     @Override
@@ -81,25 +88,43 @@ public class PercolatorBackwardsCompatibilityTests extends ESIntegTestCase {
             .setTypes(".percolator")
             .addSort("_uid", SortOrder.ASC)
             .get();
-        assertThat(searchResponse.getHits().getTotalHits(), equalTo(3L));
+        assertThat(searchResponse.getHits().getTotalHits(), equalTo(4L));
         assertThat(searchResponse.getHits().getAt(0).id(), equalTo("1"));
         assertThat(searchResponse.getHits().getAt(1).id(), equalTo("2"));
         assertThat(searchResponse.getHits().getAt(2).id(), equalTo("3"));
+        assertThat(searchResponse.getHits().getAt(3).id(), equalTo("4"));
+        assertThat(XContentMapValues.extractValue("query.script.script.inline",
+                searchResponse.getHits().getAt(3).sourceAsMap()), equalTo("return true"));
+        // we don't upgrade the script definitions so that they include explicitly the lang,
+        // because we read / parse the query at search time.
+        assertThat(XContentMapValues.extractValue("query.script.script.lang",
+                searchResponse.getHits().getAt(3).sourceAsMap()), nullValue());
 
         // verify percolate response
         PercolateResponse percolateResponse = preparePercolate(client())
+                .setIndices(INDEX_NAME)
+                .setDocumentType("message")
+                .setPercolateDoc(new PercolateSourceBuilder.DocBuilder().setDoc("{}"))
+                .get();
+
+        assertThat(percolateResponse.getCount(), equalTo(1L));
+        assertThat(percolateResponse.getMatches().length, equalTo(1));
+        assertThat(percolateResponse.getMatches()[0].getId().string(), equalTo("4"));
+
+        percolateResponse = preparePercolate(client())
             .setIndices(INDEX_NAME)
             .setDocumentType("message")
             .setPercolateDoc(new PercolateSourceBuilder.DocBuilder().setDoc("message", "the quick brown fox jumps over the lazy dog"))
             .get();
 
-        assertThat(percolateResponse.getCount(), equalTo(2L));
-        assertThat(percolateResponse.getMatches().length, equalTo(2));
+        assertThat(percolateResponse.getCount(), equalTo(3L));
+        assertThat(percolateResponse.getMatches().length, equalTo(3));
         assertThat(percolateResponse.getMatches()[0].getId().string(), equalTo("1"));
         assertThat(percolateResponse.getMatches()[1].getId().string(), equalTo("2"));
+        assertThat(percolateResponse.getMatches()[2].getId().string(), equalTo("4"));
 
         // add an extra query and verify the results
-        client().prepareIndex(INDEX_NAME, ".percolator", "4")
+        client().prepareIndex(INDEX_NAME, ".percolator", "5")
             .setSource(jsonBuilder().startObject().field("query", matchQuery("message", "fox jumps")).endObject())
             .get();
         refresh();
@@ -110,8 +135,8 @@ public class PercolatorBackwardsCompatibilityTests extends ESIntegTestCase {
             .setPercolateDoc(new PercolateSourceBuilder.DocBuilder().setDoc("message", "the quick brown fox jumps over the lazy dog"))
             .get();
 
-        assertThat(percolateResponse.getCount(), equalTo(3L));
-        assertThat(percolateResponse.getMatches().length, equalTo(3));
+        assertThat(percolateResponse.getCount(), equalTo(4L));
+        assertThat(percolateResponse.getMatches().length, equalTo(4));
         assertThat(percolateResponse.getMatches()[0].getId().string(), equalTo("1"));
         assertThat(percolateResponse.getMatches()[1].getId().string(), equalTo("2"));
         assertThat(percolateResponse.getMatches()[2].getId().string(), equalTo("4"));
@@ -131,4 +156,19 @@ public class PercolatorBackwardsCompatibilityTests extends ESIntegTestCase {
         ensureGreen(INDEX_NAME);
     }
 
+    // Fool the script service that this is the groovy script language,
+    // so that we can run a script that has no lang defined implicetely against the legacy language:
+    public static class FoolMeScriptLang extends MockScriptPlugin {
+
+        @Override
+        protected Map<String, Function<Map<String, Object>, Object>> pluginScripts() {
+            return Collections.singletonMap("return true", (vars) -> true);
+        }
+
+        @Override
+        public String pluginScriptLang() {
+            return "groovy";
+        }
+    }
+
 }

modules/percolator/src/test/java/org/elasticsearch/percolator/PercolatorFieldMapperTests.java

@@ -36,10 +36,14 @@ import org.apache.lucene.search.join.ScoreMode;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
+import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.common.xcontent.support.XContentMapValues;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.mapper.DocumentMapper;
 import org.elasticsearch.index.mapper.DocumentMapperParser;
@@ -61,6 +65,8 @@ import org.elasticsearch.index.query.functionscore.FunctionScoreQueryBuilder;
 import org.elasticsearch.index.query.functionscore.RandomScoreFunctionBuilder;
 import org.elasticsearch.indices.TermsLookup;
 import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.script.MockScriptPlugin;
+import org.elasticsearch.script.Script;
 import org.elasticsearch.test.ESSingleNodeTestCase;
 import org.elasticsearch.test.InternalSettingsPlugin;
 import org.elasticsearch.test.VersionUtils;
@@ -72,6 +78,8 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
 
 import static com.carrotsearch.randomizedtesting.RandomizedTest.getRandom;
 import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
@@ -100,7 +108,7 @@ public class PercolatorFieldMapperTests extends ESSingleNodeTestCase {
 
     @Override
     protected Collection<Class<? extends Plugin>> getPlugins() {
-        return pluginList(InternalSettingsPlugin.class, PercolatorPlugin.class);
+        return pluginList(InternalSettingsPlugin.class, PercolatorPlugin.class, FoolMeScriptPlugin.class);
     }
 
     @Before
@@ -493,4 +501,71 @@ public class PercolatorFieldMapperTests extends ESSingleNodeTestCase {
         DocumentMapper defaultMapper = parser2x.parse("type1", new CompressedXContent(mapping));
         assertEquals(mapping, defaultMapper.mappingSource().string());
     }
+
+    public void testImplicitlySetDefaultScriptLang() throws Exception {
+        addQueryMapping();
+        XContentBuilder query = jsonBuilder();
+        query.startObject();
+        query.startObject("script");
+        if (randomBoolean()) {
+            query.field("script", "return true");
+        } else {
+            query.startObject("script");
+            query.field("inline", "return true");
+            query.endObject();
+        }
+        query.endObject();
+        query.endObject();
+
+        ParsedDocument doc = mapperService.documentMapper(typeName).parse("test", typeName, "1",
+                XContentFactory.jsonBuilder().startObject()
+                        .rawField(fieldName, new BytesArray(query.string()))
+                        .endObject().bytes());
+        BytesRef querySource = doc.rootDoc().getFields(fieldType.queryBuilderField.name())[0].binaryValue();
+        Map<String, Object> parsedQuery = XContentHelper.convertToMap(new BytesArray(querySource), true).v2();
+        assertEquals(Script.DEFAULT_SCRIPT_LANG, XContentMapValues.extractValue("script.script.lang", parsedQuery));
+
+        query = jsonBuilder();
+        query.startObject();
+        query.startObject("function_score");
+        query.startArray("functions");
+        query.startObject();
+        query.startObject("script_score");
+        if (randomBoolean()) {
+            query.field("script", "return true");
+        } else {
+            query.startObject("script");
+            query.field("inline", "return true");
+            query.endObject();
+        }
+        query.endObject();
+        query.endObject();
+        query.endArray();
+        query.endObject();
+        query.endObject();
+
+        doc = mapperService.documentMapper(typeName).parse("test", typeName, "1",
+                XContentFactory.jsonBuilder().startObject()
+                        .rawField(fieldName, new BytesArray(query.string()))
+                        .endObject().bytes());
+        querySource = doc.rootDoc().getFields(fieldType.queryBuilderField.name())[0].binaryValue();
+        parsedQuery = XContentHelper.convertToMap(new BytesArray(querySource), true).v2();
+        assertEquals(Script.DEFAULT_SCRIPT_LANG,
+                ((List) XContentMapValues.extractValue("function_score.functions.script_score.script.lang", parsedQuery)).get(0));
+    }
+
+    // Just so that we store scripts in percolator queries, but not really execute these scripts.
+    public static class FoolMeScriptPlugin extends MockScriptPlugin {
+
+        @Override
+        protected Map<String, Function<Map<String, Object>, Object>> pluginScripts() {
+            return Collections.singletonMap("return true", (vars) -> true);
+        }
+
+        @Override
+        public String pluginScriptLang() {
+            return Script.DEFAULT_SCRIPT_LANG;
+        }
+    }
+
 }