1 files changed, 3 insertions, 1 deletions
diff --git a/core/src/main/java/org/elasticsearch/index/query/QueryRewriteContext.java b/core/src/main/java/org/elasticsearch/index/query/QueryRewriteContext.java
index ccca0af652..c8b5cf174f 100644
--- a/core/src/main/java/org/elasticsearch/index/query/QueryRewriteContext.java
+++ b/core/src/main/java/org/elasticsearch/index/query/QueryRewriteContext.java
@@ -86,7 +86,9 @@ public class QueryRewriteContext implements ParseFieldMatcherSupplier {
         return mapperService;
     }
 
-    /** Return the current {@link IndexReader}, or {@code null} if we are on the coordinating node. */
+    /** Return the current {@link IndexReader}, or {@code null} if no index reader is available, for
+     *  instance if we are on the coordinating node or if this rewrite context is used to index
+     *  queries (percolation). */
     public IndexReader getIndexReader() {
         return reader;
     }