Fix addChild method in Node.java

Author: jashap

modules/http2/src/main/java/org/glassfish/grizzly/http2/Node.java

@@ -110,37 +110,39 @@ protected void addChild(final Node n) {
     }
 
     /**
-     * Add a new exclusive child.  Any other children will be moved to
-     * children of this exclusive child.
+     * Add a new child. If the child is marked as exclusive, any
+     * other children will be moved to become the children of this
+     * exclusive child.
      */
-    protected void addChild(final Node n, final boolean exclusive) {
+    protected void addChild(final Node nodeBeingAddedAsChild, final boolean exclusive) {
         writeLock.lock();
         try {
             if (exclusive) {
-                n.exclusive = true;
-                if (n.firstChild != null && firstChild != null) {
+                nodeBeingAddedAsChild.exclusive = true;
+                if (nodeBeingAddedAsChild.firstChild != null && firstChild != null) {
                     Node tail = firstChild;
                     while (tail.next != null) {
                         tail = tail.next;
                     }
-                    tail.next = n.firstChild;
-                    n.firstChild.prev = tail;
-
+                    tail.next = nodeBeingAddedAsChild.firstChild;
+                    nodeBeingAddedAsChild.firstChild.prev = tail;
+                    nodeBeingAddedAsChild.firstChild = firstChild;
+                } else if (nodeBeingAddedAsChild.firstChild == null && firstChild != null) {
+                    nodeBeingAddedAsChild.firstChild = firstChild;
                 }
-                n.firstChild = firstChild;
                 firstChild = null;
-                if (n.firstChild != null) {
-                    Node t = n.firstChild;
+                if (nodeBeingAddedAsChild.firstChild != null) {
+                    Node t = nodeBeingAddedAsChild.firstChild;
                     do {
-                        t.parent = n;
+                        t.parent = nodeBeingAddedAsChild;
                     } while ((t = t.next) != null);
                 }
             }
             if (firstChild == null) {
-                firstChild = n;
+                firstChild = nodeBeingAddedAsChild;
                 firstChild.parent = this;
             } else {
-                firstChild.addSibling(n);
+                firstChild.addSibling(nodeBeingAddedAsChild);
             }
         } finally {
             writeLock.unlock();

modules/http2/src/test/java/org/glassfish/grizzly/http2/NaryTreeTest.java

@@ -115,6 +115,61 @@ public void addExclusiveChild2() {
         assertEquals(3, root.firstChild.firstChild.firstChild.parent.id);
     }
 
+    @Test
+    public void addExclusiveChild3() {
+        final Node root = new TestNode(0);
+        final Node childToAdd = new TestNode(1);
+        childToAdd.addChild(new TestNode(2));
+        root.addChild(childToAdd, true);
+        assertEquals(1, root.firstChild.id);
+        assertTrue(root.firstChild.exclusive);
+        assertEquals(0, root.firstChild.parent.id);
+        assertEquals(2, root.firstChild.firstChild.id);
+        assertEquals(1, root.firstChild.firstChild.parent.id);
+        assertNull(root.firstChild.next);
+        assertNull(root.firstChild.prev);
+    }
+
+    @Test
+    public void addExclusiveChild4() {
+        final Node root = new TestNode(0);
+        root.addChild(new TestNode(1));
+        final Node childToAdd = new TestNode(2);
+        root.addChild(childToAdd, true);
+        assertEquals(2, root.firstChild.id);
+        assertTrue(root.firstChild.exclusive);
+        assertEquals(0, root.firstChild.parent.id);
+        assertEquals(1, root.firstChild.firstChild.id);
+        assertEquals(2, root.firstChild.firstChild.parent.id);
+        assertNull(root.firstChild.next);
+        assertNull(root.firstChild.prev);
+    }
+
+    @Test
+    public void addExclusiveChild5() {
+        final Node root = new TestNode(0);
+        root.addChild(new TestNode(1));
+        root.addChild(new TestNode(2));
+        final Node childToAdd = new TestNode(3);
+        childToAdd.addChild(new TestNode(4));
+        childToAdd.addChild(new TestNode(5));
+        root.addChild(childToAdd, true);
+
+        assertEquals(0, root.id);
+        assertEquals(3, root.firstChild.id);
+        assertEquals(2, root.firstChild.firstChild.id);
+        assertEquals(1, root.firstChild.firstChild.next.id);
+        assertEquals(5, root.firstChild.firstChild.next.next.id);
+        assertEquals(4, root.firstChild.firstChild.next.next.next.id);
+
+        assertTrue(root.firstChild.exclusive);
+        assertEquals(0, root.firstChild.parent.id);
+        assertEquals(3, root.firstChild.firstChild.parent.id);
+        assertEquals(3, root.firstChild.firstChild.next.next.parent.id);
+        assertNull(root.firstChild.next);
+        assertNull(root.firstChild.prev);
+    }
+
     @Test
     public void find() {
         createAndValidate(); // No Exception thrown, find works.