Retarget key events to the parent presshell if we have no root content. Bug

303260, r=mats, sr=roc

docshell/base/nsDocShell.cpp

@@ -8555,6 +8555,27 @@ nsDocShell::SetHasFocus(PRBool aHasFocus)
   return NS_OK;
 }
 
+// Find an nsICanvasFrame under aFrame.  Only search the principal
+// child lists.  aFrame must be non-null.
+static nsICanvasFrame* FindCanvasFrame(nsIFrame* aFrame)
+{
+    nsICanvasFrame* canvasFrame;
+    if (NS_SUCCEEDED(CallQueryInterface(aFrame, &canvasFrame))) {
+        return canvasFrame;
+    }
+
+    nsIFrame* kid = aFrame->GetFirstChild(nsnull);
+    while (kid) {
+        canvasFrame = FindCanvasFrame(kid);
+        if (canvasFrame) {
+            return canvasFrame;
+        }
+        kid = kid->GetNextSibling();
+    }
+
+    return nsnull;
+}
+
 //-------------------------------------------------------
 // Tells the HTMLFrame/CanvasFrame that is now has focus
 NS_IMETHODIMP
@@ -8571,17 +8592,28 @@ nsDocShell::SetCanvasHasFocus(PRBool aCanvasHasFocus)
   if (!doc) return NS_ERROR_FAILURE;
 
   nsIContent *rootContent = doc->GetRootContent();
-  if (!rootContent) return NS_ERROR_FAILURE;
-
-  nsIFrame* frame = presShell->GetPrimaryFrameFor(rootContent);
-  if (frame) {
-    frame = frame->GetParent();
-    if (frame) {
-      nsICanvasFrame* canvasFrame;
-      if (NS_SUCCEEDED(frame->QueryInterface(NS_GET_IID(nsICanvasFrame), (void**)&canvasFrame)))
-        return canvasFrame->SetHasFocus(aCanvasHasFocus);
-    }
+  if (rootContent) {
+      nsIFrame* frame = presShell->GetPrimaryFrameFor(rootContent);
+      if (frame) {
+          frame = frame->GetParent();
+          if (frame) {
+              nsICanvasFrame* canvasFrame;
+              if (NS_SUCCEEDED(CallQueryInterface(frame, &canvasFrame))) {
+                  return canvasFrame->SetHasFocus(aCanvasHasFocus);
+              }
+          }
+      }
+  } else {
+      // Look for the frame the hard way
+      nsIFrame* frame = presShell->GetRootFrame();
+      if (frame) {
+          nsICanvasFrame* canvasFrame = FindCanvasFrame(frame);
+          if (canvasFrame) {
+              return canvasFrame->SetHasFocus(aCanvasHasFocus);
+          }
+      }      
   }
+  
   return NS_ERROR_FAILURE;
 }
 

layout/base/nsPresShell.cpp

@@ -5804,9 +5804,10 @@ nsresult PresShell::RetargetEventToParent(nsIView         *aView,
   // We do this for non-mouse events in zombie documents.
   // That way at least the UI key bindings can work.
 
-  // First, eliminate the focus ring in the current docshell, which 
-  // is  now a zombie. If we key navigate, it won't be within this
-  // docshell, until the newly loading document is displayed.
+  // First, eliminate the focus ring in the current docshell, which is
+  // now a zombie. If we key navigate, it won't be within this
+  // docshell, until the newly loading document is displayed or we
+  // have a root content again.
 
   nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
   // hold a reference to the ESM across event dispatch
@@ -5814,8 +5815,10 @@ nsresult PresShell::RetargetEventToParent(nsIView         *aView,
 
   esm->SetContentState(nsnull, NS_EVENT_STATE_FOCUS);
   esm->SetFocusedContent(nsnull);
-  ContentStatesChanged(mDocument, aZombieFocusedContent,
-                       nsnull, NS_EVENT_STATE_FOCUS);
+  if (aZombieFocusedContent) {
+    ContentStatesChanged(mDocument, aZombieFocusedContent,
+                         nsnull, NS_EVENT_STATE_FOCUS);
+  }
 
   // Next, update the display so the old focus ring is no longer visible
 
@@ -6019,7 +6022,7 @@ PresShell::HandleEvent(nsIView         *aView,
         }
         mCurrentEventFrame = nsnull; // XXXldb Isn't it already?
       }
-      if (mCurrentEventContent && InZombieDocument(mCurrentEventContent)) {
+      if (!mCurrentEventContent || InZombieDocument(mCurrentEventContent)) {
         return RetargetEventToParent(aView, aEvent, aEventStatus,
                                      mCurrentEventContent);
       }