Fix encoding of dynamic arrays in ignored source (elastic#112713) (elastic#112716)

Author: lkts

docs/changelog/112713.yaml

@@ -0,0 +1,5 @@
+pr: 112713
+summary: Fix encoding of dynamic arrays in ignored source
+area: Logs
+type: bug
+issues: []

server/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java

@@ -639,7 +639,7 @@ private static void parseArrayDynamic(DocumentParserContext context, String curr
                         context.addIgnoredField(
                             IgnoredSourceFieldMapper.NameValue.fromContext(
                                 context,
-                                currentFieldName,
+                                context.path().pathAsText(currentFieldName),
                                 XContentDataHelper.encodeToken(context.parser())
                             )
                         );

server/src/test/java/org/elasticsearch/index/mapper/IgnoredSourceFieldMapperTests.java

@@ -213,6 +213,18 @@ public void testMultipleIgnoredFieldsManyObjects() throws IOException {
         );
     }
 
+    public void testIgnoredDynamicArrayNestedInObject() throws IOException {
+        int intValue = randomInt();
+
+        String syntheticSource = getSyntheticSourceWithFieldLimit(b -> {
+            b.startObject("bar");
+            b.field("a", List.of(intValue, intValue));
+            b.endObject();
+        });
+        assertEquals(String.format(Locale.ROOT, """
+            {"bar":{"a":[%s,%s]}}""", intValue, intValue), syntheticSource);
+    }
+
     public void testDisabledRootObjectSingleField() throws IOException {
         String name = randomAlphaOfLength(20);
         DocumentMapper documentMapper = createMapperService(topMapping(b -> {