Bug 1024454 (Part 1) - Eagerly propagate dirty bits so absolute child…

…ren of table parts get reflowed reliably. r=dbaron

layout/generic/nsFrame.cpp

@@ -4354,6 +4354,18 @@ nsFrame::ReflowAbsoluteFrames(nsPresContext*           aPresContext,
   }
 }
 
+void
+nsFrame::PushDirtyBitToAbsoluteFrames()
+{
+  if (!(GetStateBits() & NS_FRAME_IS_DIRTY)) {
+    return;  // No dirty bit to push.
+  }
+  if (!HasAbsolutelyPositionedChildren()) {
+    return;  // No absolute children to push to.
+  }
+  GetAbsoluteContainingBlock()->MarkAllFramesDirty();
+}
+
 /* virtual */ bool
 nsFrame::CanContinueTextRun() const
 {

layout/generic/nsFrame.h

@@ -331,6 +331,20 @@ class nsFrame : public nsBox
                                       const nsHTMLReflowState& aReflowState,
                                       nsReflowStatus&          aStatus,
                                       bool                     aConstrainHeight = true);
+
+  /*
+   * If this frame is dirty, marks all absolutely-positioned children of this
+   * frame dirty. If this frame isn't dirty, or if there are no
+   * absolutely-positioned children, does nothing.
+   *
+   * It's necessary to use PushDirtyBitToAbsoluteFrames() when you plan to
+   * reflow this frame's absolutely-positioned children after the dirty bit on
+   * this frame has already been cleared, which prevents nsHTMLReflowState from
+   * propagating the dirty bit normally. This situation generally only arises
+   * when a multipass layout algorithm is used.
+   */
+  void PushDirtyBitToAbsoluteFrames();
+
   virtual bool CanContinueTextRun() const MOZ_OVERRIDE;
 
   virtual bool UpdateOverflow() MOZ_OVERRIDE;

layout/tables/nsTableCellFrame.cpp

@@ -1019,6 +1019,11 @@ nsTableCellFrame::Reflow(nsPresContext*           aPresContext,
   // remember the desired size for this reflow
   SetDesiredSize(aDesiredSize);
 
+  // Any absolutely-positioned children will get reflowed in
+  // nsFrame::FixupPositionedTableParts in another pass, so propagate our
+  // dirtiness to them before our parent clears our dirty bits.
+  PushDirtyBitToAbsoluteFrames();
+
   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
 }
 

layout/tables/nsTableRowFrame.cpp

@@ -1064,6 +1064,11 @@ nsTableRowFrame::Reflow(nsPresContext*          aPresContext,
     InvalidateFrame();
   }
 
+  // Any absolutely-positioned children will get reflowed in
+  // nsFrame::FixupPositionedTableParts in another pass, so propagate our
+  // dirtiness to them before our parent clears our dirty bits.
+  PushDirtyBitToAbsoluteFrames();
+
   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
 }
 

layout/tables/nsTableRowGroupFrame.cpp

@@ -1357,6 +1357,12 @@ nsTableRowGroupFrame::Reflow(nsPresContext*           aPresContext,
   }
 
   FinishAndStoreOverflow(&aDesiredSize);
+
+  // Any absolutely-positioned children will get reflowed in
+  // nsFrame::FixupPositionedTableParts in another pass, so propagate our
+  // dirtiness to them before our parent clears our dirty bits.
+  PushDirtyBitToAbsoluteFrames();
+
   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
 }