Bug 380288 - NPE switching to the Breakpoints View

Added guard to prevent updating viewer while input == null.

5 files changed, 40 insertions, 8 deletions

diff --git a/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/StateTests.java b/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/StateTests.java
index 3f63ba195..9a6ac7950 100644
--- a/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/StateTests.java
+++ b/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/StateTests.java
@@ -1130,4 +1130,38 @@ abstract public class StateTests extends TestCase implements ITestModelUpdatesLi
         Assert.assertTrue("RESTORE started before SAVE to complete", fListener.isFinished(STATE_SAVE_COMPLETE));        
     }    
 
+    /**
+     * This test tries to restore a viewer state while input == null.
+     * See: Bug 380288 - NPE switching to the Breakpoints View
+     */
+    public void testUpdateWithNullInput() throws InterruptedException {
+        TestModel model = TestModel.simpleMultiLevel();
+        fViewer.setAutoExpandLevel(-1);
+
+        // Create the listener
+        fListener.reset(TreePath.EMPTY, model.getRootElement(), -1, false, false); 
+
+        // Set the input into the view and update the view.
+        fViewer.setInput(model.getRootElement());
+        while (!fListener.isFinished()) if (!fDisplay.readAndDispatch ()) Thread.sleep(0);
+        model.validateData(fViewer, TreePath.EMPTY);
+
+        ModelDelta expandedState = new ModelDelta(model.getRootElement(), IModelDelta.NO_CHANGE);
+        fViewer.saveElementState(TreePath.EMPTY, expandedState, IModelDelta.EXPAND);
+        
+        // Refresh the viewer so that updates are generated.
+        fListener.reset();
+        fListener.addChildreCountUpdate(TreePath.EMPTY);
+        model.postDelta(new ModelDelta(model.getRootElement(), IModelDelta.CONTENT));
+        
+        // Wait for the delta to be processed.
+        while (!fListener.isFinished(MODEL_CHANGED_COMPLETE | CHILD_COUNT_UPDATES)) 
+        	if (!fDisplay.readAndDispatch ()) Thread.sleep(0);
+        
+        fViewer.setInput(null);
+        fViewer.updateViewer(expandedState);
+
+        while (!fListener.isFinished(CONTENT_COMPLETE | VIEWER_UPDATES_RUNNING)) if (!fDisplay.readAndDispatch ()) Thread.sleep(0);
+        
+    }
 }
diff --git a/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/UpdateTests.java b/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/UpdateTests.java
index a499ae5e7..1b23bdb4e 100644
--- a/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/UpdateTests.java
+++ b/org.eclipse.debug.tests/src/org/eclipe/debug/tests/viewer/model/UpdateTests.java
@@ -637,7 +637,6 @@ abstract public class UpdateTests extends TestCase implements ITestModelUpdatesL
         
     }
     
-    
     private void completeQueuedUpdatesOfType(TestModel model, Class updateClass) {
         List updatesToComplete = new LinkedList();
         
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenCountUpdate.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenCountUpdate.java
index 871c84a2c..8d89714e7 100644
--- a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenCountUpdate.java
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenCountUpdate.java
@@ -232,9 +232,7 @@ class ChildrenCountUpdate extends ViewerUpdateMonitor implements IChildrenCountU
     protected boolean doEquals(ViewerUpdateMonitor update) {
         return 
             update instanceof ChildrenCountUpdate && 
-            // Bug 380288 - workaround a race condition where update is initialized with null input.
-            ((getViewerInput() == null && update.getViewerInput() == null) || 
-             (getViewerInput() != null && getViewerInput().equals(update.getViewerInput()))) && 
+            getViewerInput().equals(update.getViewerInput()) && 
             getElementPath().equals(getElementPath());
     }
     
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenUpdate.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenUpdate.java
index 07351334e..6397a2bdc 100644
--- a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenUpdate.java
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ChildrenUpdate.java
@@ -223,16 +223,13 @@ public class ChildrenUpdate extends ViewerUpdateMonitor implements IChildrenUpda
             update instanceof ChildrenUpdate &&
             ((ChildrenUpdate)update).getOffset() == getOffset() &&
             ((ChildrenUpdate)update).getLength() == getLength() &&
-            // Bug 380288 - workaround a race condition where update is initialized with null input.
-            ((getViewerInput() == null && update.getViewerInput() == null) || 
-             (getViewerInput() != null && getViewerInput().equals(update.getViewerInput()))) && 
+            getViewerInput().equals(update.getViewerInput()) && 
             getElementPath().equals(getElementPath());
     }
 
     protected int doHashCode() {
         return (int)Math.pow(
             (getClass().hashCode() + getViewerInput().hashCode() + getElementPath().hashCode()) * (getOffset() + 2),
-            
             getLength() + 2);
     }
 
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/TreeModelContentProvider.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/TreeModelContentProvider.java
index f488f32e6..b95ffa248 100644
--- a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/TreeModelContentProvider.java
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/TreeModelContentProvider.java
@@ -426,6 +426,10 @@ public class TreeModelContentProvider implements ITreeModelContentProvider, ICon
     }
 
     public void updateModel(IModelDelta delta, int mask) {
+    	// Processing deltas with null input leads to NPEs
+    	// (Bug 380288 - NPE switching to the Breakpoints View)
+    	if (getViewer() == null || getViewer().getInput() == null) return;
+    	
         IModelDelta[] deltaArray = new IModelDelta[] { delta };
         updateNodes(deltaArray, mask & (IModelDelta.REMOVED | IModelDelta.UNINSTALL));
         updateNodes(deltaArray, mask & ITreeModelContentProvider.UPDATE_MODEL_DELTA_FLAGS