Report incomplete reflow status as appropriate when frame tree is too deep. (Bug 619021) r=roc a2.0=blocking

layout/generic/nsBlockFrame.cpp

@@ -993,8 +993,7 @@ nsBlockFrame::Reflow(nsPresContext*           aPresContext,
   // delete the line with the line cursor.
   ClearLineCursor();
 
-  if (IsFrameTreeTooDeep(aReflowState, aMetrics)) {
+  if (IsFrameTreeTooDeep(aReflowState, aMetrics, aStatus)) {
-    aStatus = NS_FRAME_COMPLETE;
     return NS_OK;
   }
 

layout/generic/nsFrame.cpp

@@ -4551,7 +4551,8 @@ nsIFrame::CheckInvalidateSizeChange(const nsRect& aOldRect,
 
 PRBool
 nsFrame::IsFrameTreeTooDeep(const nsHTMLReflowState& aReflowState,
-                            nsHTMLReflowMetrics& aMetrics)
+                            nsHTMLReflowMetrics& aMetrics,
+                            nsReflowStatus& aStatus)
 {
   if (aReflowState.mReflowDepth >  MAX_FRAME_DEPTH) {
     NS_WARNING("frame tree too deep; setting zero size and returning");
@@ -4562,6 +4563,16 @@ nsFrame::IsFrameTreeTooDeep(const nsHTMLReflowState& aReflowState,
     aMetrics.ascent = 0;
     aMetrics.mCarriedOutBottomMargin.Zero();
     aMetrics.mOverflowAreas.Clear();
+
+    if (GetNextInFlow()) {
+      // Reflow depth might vary between reflows, so we might have
+      // successfully reflowed and split this frame before.  If so, we
+      // shouldn't delete its continuations.
+      aStatus = NS_FRAME_NOT_COMPLETE;
+    } else {
+      aStatus = NS_FRAME_COMPLETE;
+    }
+
     return PR_TRUE;
   }
   mState &= ~NS_FRAME_TOO_DEEP_IN_FRAME_TREE;

layout/generic/nsFrame.h

@@ -386,13 +386,14 @@ public:
    */
   void CheckInvalidateSizeChange(nsHTMLReflowMetrics&     aNewDesiredSize);
 
-  // Helper function that tests if the frame tree is too deep; if it
+  // Helper function that tests if the frame tree is too deep; if it is
-  // is it marks the frame as "unflowable" and zeros out the metrics
+  // it marks the frame as "unflowable", zeroes out the metrics, sets
-  // and returns PR_TRUE. Otherwise, the frame is unmarked
+  // the reflow status, and returns PR_TRUE. Otherwise, the frame is
-  // "unflowable" and the metrics are not touched and PR_FALSE is
+  // unmarked "unflowable" and the metrics and reflow status are not
-  // returned.
+  // touched and PR_FALSE is returned.
   PRBool IsFrameTreeTooDeep(const nsHTMLReflowState& aReflowState,
-                            nsHTMLReflowMetrics& aMetrics);
+                            nsHTMLReflowMetrics& aMetrics,
+                            nsReflowStatus& aStatus);
 
   // Do the work for getting the parent style context frame so that
   // other frame's |GetParentStyleContextFrame| methods can call this

layout/generic/nsInlineFrame.cpp

@@ -392,8 +392,7 @@ nsInlineFrame::Reflow(nsPresContext*          aPresContext,
     }
   }
 
-  if (IsFrameTreeTooDeep(aReflowState, aMetrics)) {
+  if (IsFrameTreeTooDeep(aReflowState, aMetrics, aStatus)) {
-    aStatus = NS_FRAME_COMPLETE;
     return NS_OK;
   }