OAK-11379 Ignore deleted ordered children in JsonSerializer output (#1974)

Author: jelmini

oak-store-spi/src/main/java/org/apache/jackrabbit/oak/json/JsonSerializer.java

@@ -192,7 +192,10 @@ private Iterable<? extends ChildNodeEntry> getChildNodeEntries(NodeState node, S
             List<ChildNodeEntry> entries = new ArrayList<>(names.size());
             for (String name : names) {
                 try {
-                    entries.add(new MemoryChildNodeEntry(name, node.getChildNode(name)));
+                    NodeState childNode = node.getChildNode(name);
+                    if (childNode.exists()) {
+                        entries.add(new MemoryChildNodeEntry(name, childNode));
+                    }
                 } catch (Throwable t) {
                     if (catchExceptions) {
                         String message = "Cannot read node " + basePath + "/" + name + " : " + t.getMessage();

oak-store-spi/src/test/java/org/apache/jackrabbit/oak/json/JsonSerializerTest.java

@@ -22,7 +22,6 @@
 import static org.junit.Assert.assertEquals;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 
 import org.apache.jackrabbit.oak.api.Type;
@@ -41,8 +40,11 @@ public void childOrder() throws Exception{
         builder.child("a");
         builder.child("b");
         builder.child("c");
-        List<String> expectedOrder = Arrays.asList("a", "c", "b");
-        builder.setProperty(":childOrder", expectedOrder, Type.NAMES);
+        builder.child("d");
+        builder.setProperty(":childOrder", List.of("a", "c", "b", "d"), Type.NAMES);
+
+        // A removed child should not be included in the output
+        builder.getChildNode("c").remove();
 
         NodeState state = builder.getNodeState();
         String json = serialize(state);
@@ -60,7 +62,7 @@ public void childOrder() throws Exception{
 
         } while (reader.matches(','));
 
-        assertEquals(expectedOrder, childNames);
+        assertEquals(List.of("a", "b", "d"), childNames);
     }
 
     private String serialize(NodeState nodeState){