From 18c295cada4af576ff1e2211b87fdf6696aefeed Mon Sep 17 00:00:00 2001
From: James Baiera <james.baiera@gmail.com>
Date: Thu, 25 Sep 2025 19:14:56 -0400
Subject: [PATCH 1/2] Correctly apply field path to JSON processor when adding
 contents to document root (#135479)

Processor now correctly uses ingest document methods to obtain field data.

---------

Co-authored-by: Joe Gallo <joegallo@gmail.com>
---
 docs/changelog/135479.yaml                    |  6 +++++
 .../ingest/common/JsonProcessor.java          |  9 ++++++--
 .../ingest/common/JsonProcessorTests.java     | 23 +++++++++++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 docs/changelog/135479.yaml

diff --git a/docs/changelog/135479.yaml b/docs/changelog/135479.yaml
new file mode 100644
index 0000000000000..fa6f5ea620550
--- /dev/null
+++ b/docs/changelog/135479.yaml
@@ -0,0 +1,6 @@
+pr: 135479
+summary: Correctly apply field path to JSON processor when adding contents to document
+  root
+area: Ingest Node
+type: bug
+issues: []
diff --git a/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/JsonProcessor.java b/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/JsonProcessor.java
index 69c5699912f5d..fe4137fb686fc 100644
--- a/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/JsonProcessor.java
+++ b/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/JsonProcessor.java
@@ -148,6 +148,10 @@ public static void apply(
         boolean strictJsonParsing
     ) {
         Object value = apply(ctx.get(fieldName), allowDuplicateKeys, strictJsonParsing);
+        mergeParsedJson(ctx, value, conflictStrategy);
+    }
+
+    private static void mergeParsedJson(Map<String, Object> ctx, Object value, ConflictStrategy conflictStrategy) {
         if (value instanceof Map) {
             @SuppressWarnings("unchecked")
             Map<String, Object> map = (Map<String, Object>) value;
@@ -183,10 +187,11 @@ public static void recursiveMerge(Map<String, Object> target, Map<String, Object
 
     @Override
     public IngestDocument execute(IngestDocument document) throws Exception {
+        Object value = apply(document.getFieldValue(field, Object.class), allowDuplicateKeys, strictJsonParsing);
         if (addToRoot) {
-            apply(document.getSourceAndMetadata(), field, allowDuplicateKeys, addToRootConflictStrategy, strictJsonParsing);
+            mergeParsedJson(document.getSourceAndMetadata(), value, addToRootConflictStrategy);
         } else {
-            document.setFieldValue(targetField, apply(document.getFieldValue(field, Object.class), allowDuplicateKeys, strictJsonParsing));
+            document.setFieldValue(targetField, value);
         }
         return document;
     }
diff --git a/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java b/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java
index ffdebed8e524a..f61d7d09c8b9c 100644
--- a/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java
+++ b/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java
@@ -12,6 +12,7 @@
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.ingest.IngestDocument;
+import org.elasticsearch.ingest.IngestPipelineTestUtils;
 import org.elasticsearch.ingest.RandomDocumentPicks;
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xcontent.XContentBuilder;
@@ -166,6 +167,28 @@ public void testAddToRoot() throws Exception {
         assertEquals("see", sourceAndMetadata.get("c"));
     }
 
+    public void testAddToRootNestedField() throws Exception {
+        String processorTag = randomAlphaOfLength(3);
+        String randomTargetField = randomAlphaOfLength(2);
+        JsonProcessor jsonProcessor = new JsonProcessor(processorTag, null, "a.b", randomTargetField, true, REPLACE, false);
+
+        String json = "{\"a\": 1, \"b\": 2}";
+        Map<String, Object> subfield = new HashMap<>();
+        subfield.put("b", json);
+
+        Map<String, Object> document = new HashMap<>();
+        document.put("a", subfield);
+        document.put("c", "see");
+
+        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random(), document);
+        ingestDocument = IngestPipelineTestUtils.runWithRandomAccessPattern(ingestDocument, jsonProcessor);
+
+        Map<String, Object> sourceAndMetadata = ingestDocument.getSourceAndMetadata();
+        assertEquals(1, sourceAndMetadata.get("a"));
+        assertEquals(2, sourceAndMetadata.get("b"));
+        assertEquals("see", sourceAndMetadata.get("c"));
+    }
+
     public void testDuplicateKeys() throws Exception {
         String processorTag = randomAlphaOfLength(3);
         JsonProcessor lenientJsonProcessor = new JsonProcessor(processorTag, null, "a", null, true, REPLACE, true);

From e1c4e52691fb16de4a54d1ab3b6c00c243e5da37 Mon Sep 17 00:00:00 2001
From: James Baiera <james.baiera@gmail.com>
Date: Fri, 26 Sep 2025 13:50:40 -0400
Subject: [PATCH 2/2] Remove missing test util

---
 .../org/elasticsearch/ingest/common/JsonProcessorTests.java    | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java b/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java
index f61d7d09c8b9c..3873174ec9c10 100644
--- a/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java
+++ b/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/JsonProcessorTests.java
@@ -12,7 +12,6 @@
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.ingest.IngestDocument;
-import org.elasticsearch.ingest.IngestPipelineTestUtils;
 import org.elasticsearch.ingest.RandomDocumentPicks;
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xcontent.XContentBuilder;
@@ -181,7 +180,7 @@ public void testAddToRootNestedField() throws Exception {
         document.put("c", "see");
 
         IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random(), document);
-        ingestDocument = IngestPipelineTestUtils.runWithRandomAccessPattern(ingestDocument, jsonProcessor);
+        jsonProcessor.execute(ingestDocument);
 
         Map<String, Object> sourceAndMetadata = ingestDocument.getSourceAndMetadata();
         assertEquals(1, sourceAndMetadata.get("a"));