Render completely when the response is malformed

2 files changed, 53 insertions, 4 deletions

diff --git a/container-core/src/main/java/com/yahoo/processing/rendering/AsynchronousSectionedRenderer.java b/container-core/src/main/java/com/yahoo/processing/rendering/AsynchronousSectionedRenderer.java
index aa753beb6a7..2749b73272d 100644
--- a/container-core/src/main/java/com/yahoo/processing/rendering/AsynchronousSectionedRenderer.java
+++ b/container-core/src/main/java/com/yahoo/processing/rendering/AsynchronousSectionedRenderer.java
@@ -404,11 +404,15 @@ public abstract class AsynchronousSectionedRenderer<RESPONSE extends Response> e
             }
         }
 
-        /**
-         * Renders a list
-         */
+        /** Renders a list. */
         private void renderDataList(DataList list) throws IOException {
             final boolean ordered = isOrdered(list);
+            if (list.asList() == null) {
+                logger.log(Level.WARNING, "DataList.asList() returned null, indicating it is closed. " +
+                                          "This is likely caused by adding the same list multiple " +
+                                          "times in the response.");
+                return;
+            }
             while (currentIndex < list.asList().size()) {
                 Data data = list.get(currentIndex++);
                 if (data instanceof DataList) {
diff --git a/container-core/src/test/java/com/yahoo/processing/rendering/AsynchronousSectionedRendererTest.java b/container-core/src/test/java/com/yahoo/processing/rendering/AsynchronousSectionedRendererTest.java
index fb8aca95d9a..a4d5649a7f3 100644
--- a/container-core/src/test/java/com/yahoo/processing/rendering/AsynchronousSectionedRendererTest.java
+++ b/container-core/src/test/java/com/yahoo/processing/rendering/AsynchronousSectionedRendererTest.java
@@ -189,6 +189,18 @@ public class AsynchronousSectionedRendererTest {
                 render(dataList));
     }
 
+    /** Validate we get a full response with a malformed response structure. */
+    @Test
+    void testRenderingOfListsAddedTwice() throws Exception {
+        StringDataList dataList = createDataListWithReusedSublist();
+
+        TestRenderer renderer = new TestRenderer();
+        renderer.init();
+
+        assertEquals(" beginResponse beginList[[[]], []] beginList[[]] beginList[] endList[] endList[[]] beginList[] endList[] endList[[[]], []] endResponse",
+                     render(renderer, dataList));
+    }
+
     public StringDataList createDataList() {
         Request request = new Request();
         StringDataList dataList = new StringDataList(request);
@@ -200,6 +212,20 @@ public class AsynchronousSectionedRendererTest {
         return dataList;
     }
 
+    public StringDataList createDataListWithReusedSublist() {
+        Request request = new Request();
+        StringDataList dataList = new StringDataList(request);
+
+        StringDataList group1 = new StringDataList(request);
+        dataList.add(group1);
+
+        StringDataList group2 = new StringDataList(request);
+        group1.add(group2);
+
+        dataList.add(group2); // Bug: This should not be added twice
+        return dataList;
+    }
+
     public StringDataList createDataListWithStrangeStrings() {
         Request request = new Request();
         StringDataList dataList = new StringDataList(request);
@@ -325,6 +351,7 @@ public class AsynchronousSectionedRendererTest {
     }
 
     private static abstract class StringData extends ListenableFreezableClass implements Data {
+
         private final Request request;
 
         private StringData(Request request) {
@@ -342,6 +369,7 @@ public class AsynchronousSectionedRendererTest {
         public String toString() {
             return getString();
         }
+
     }
 
     private class StringDataItem extends StringData {
@@ -361,7 +389,8 @@ public class AsynchronousSectionedRendererTest {
 
     private class StringDataList extends StringData implements DataList<StringData> {
 
-        private final ArrayList<StringData> list = new ArrayList<>();
+        private ArrayList<StringData> list = new ArrayList<>();
+        private String stringValue = null; // set on close
 
         private final IncomingData incomingData;
 
@@ -404,8 +433,24 @@ public class AsynchronousSectionedRendererTest {
 
         @Override
         public String getString() {
+            if (stringValue != null) return stringValue;
             return list.toString();
         }
+
+        @Override
+        public void close() {
+            if (list == null) return; // Already closed
+            stringValue = list.toString();
+            list = null;
+        }
+
+        @Override
+        public StringDataList clone() {
+            var clone = new StringDataList(request());
+            clone.list = new ArrayList<>(list);
+            return clone;
+        }
+
     }
 
     private static class NoopProcessor extends Processor {