From fa8b53c57c38151414f730fb3ac3b30e2e908751 Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Fri, 24 Jul 2009 09:32:32 -0400
Subject: [PATCH] Bug 505482.  Make sure to not leave frames on overflow lists
 when we interrupt reflow.  Also fixes bug 478527 and bug 496742.  r=roc

---
 layout/generic/nsBlockFrame.cpp     | 10 +++++++++
 layout/generic/nsColumnSetFrame.cpp |  3 +++
 layout/generic/nsIFrame.h           |  6 ++++++
 layout/generic/nsInlineFrame.cpp    | 33 +++++++++++++++++++++++++++++
 layout/generic/nsInlineFrame.h      |  4 ++++
 5 files changed, 56 insertions(+)

diff --git a/layout/generic/nsBlockFrame.cpp b/layout/generic/nsBlockFrame.cpp
index 109c989fe5d..429367e4ba6 100644
--- a/layout/generic/nsBlockFrame.cpp
+++ b/layout/generic/nsBlockFrame.cpp
@@ -1857,6 +1857,7 @@ nsBlockFrame::ReflowDirtyLines(nsBlockReflowState& aState)
       aState.ReconstructMarginAbove(line);
     }
 
+    PRBool reflowedPrevLine = !needToRecoverState;
     if (needToRecoverState) {
       needToRecoverState = PR_FALSE;
 
@@ -2001,6 +2002,15 @@ nsBlockFrame::ReflowDirtyLines(nsBlockReflowState& aState)
       }
 
       needToRecoverState = PR_TRUE;
+
+      if (reflowedPrevLine && !line->IsBlock() &&
+          aState.mPresContext->HasPendingInterrupt()) {
+        // Need to make sure to pull overflows from any prev-in-flows
+        for (nsIFrame* inlineKid = line->mFirstChild; inlineKid;
+             inlineKid = inlineKid->GetFirstChild(nsnull)) {
+          inlineKid->PullOverflowsFromPrevInFlow();
+        }
+      }
     }
 
     // Record if we need to clear floats before reflowing the next
diff --git a/layout/generic/nsColumnSetFrame.cpp b/layout/generic/nsColumnSetFrame.cpp
index 4f678a19567..9b5eabcf91f 100644
--- a/layout/generic/nsColumnSetFrame.cpp
+++ b/layout/generic/nsColumnSetFrame.cpp
@@ -901,6 +901,9 @@ nsColumnSetFrame::Reflow(nsPresContext*           aPresContext,
                          const nsHTMLReflowState& aReflowState,
                          nsReflowStatus&          aStatus)
 {
+  // Don't support interruption in columns
+  nsPresContext::InterruptPreventer noInterrupts(aPresContext);
+
   DO_GLOBAL_REFLOW_COUNT("nsColumnSetFrame");
   DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
 
diff --git a/layout/generic/nsIFrame.h b/layout/generic/nsIFrame.h
index bd23376e622..f74ee20b08a 100644
--- a/layout/generic/nsIFrame.h
+++ b/layout/generic/nsIFrame.h
@@ -2315,6 +2315,12 @@ NS_PTR_TO_INT32(frame->GetProperty(nsGkAtoms::embeddingLevel))
    */
   virtual nsILineIterator* GetLineIterator() = 0;
 
+  /**
+   * If this frame is a next-in-flow, and its prev-in-flow has something on its
+   * overflow list, pull those frames into the child list of this one.
+   */
+  virtual void PullOverflowsFromPrevInFlow() {}
+
 protected:
   // Members
   nsRect           mRect;
diff --git a/layout/generic/nsInlineFrame.cpp b/layout/generic/nsInlineFrame.cpp
index 3a42e236da6..c347c001990 100644
--- a/layout/generic/nsInlineFrame.cpp
+++ b/layout/generic/nsInlineFrame.cpp
@@ -398,6 +398,21 @@ nsInlineFrame::CanContinueTextRun() const
   return PR_TRUE;
 }
 
+/* virtual */ void
+nsInlineFrame::PullOverflowsFromPrevInFlow()
+{
+  nsInlineFrame* prevInFlow = static_cast<nsInlineFrame*>(GetPrevInFlow());
+  if (prevInFlow) {
+    nsPresContext* presContext = PresContext();
+    nsIFrame* prevOverflowFrames =
+      prevInFlow->GetOverflowFrames(presContext, PR_TRUE);
+    if (prevOverflowFrames) {
+      // Assume that our prev-in-flow has the same line container that we do.
+      mFrames.InsertFrames(this, nsnull, prevOverflowFrames);
+    }
+  }
+}
+
 nsresult
 nsInlineFrame::ReflowFrames(nsPresContext* aPresContext,
                             const nsHTMLReflowState& aReflowState,
@@ -1036,6 +1051,24 @@ nsFirstLineFrame::Reflow(nsPresContext* aPresContext,
   return rv;
 }
 
+/* virtual */ void
+nsFirstLineFrame::PullOverflowsFromPrevInFlow()
+{
+  nsFirstLineFrame* prevInFlow = static_cast<nsFirstLineFrame*>(GetPrevInFlow());
+  if (prevInFlow) {
+    nsPresContext* presContext = PresContext();
+    nsIFrame* prevOverflowFrames =
+      prevInFlow->GetOverflowFrames(presContext, PR_TRUE);
+    if (prevOverflowFrames) {
+      nsFrameList frames(prevOverflowFrames);
+
+      // Assume that our prev-in-flow has the same line container that we do.
+      mFrames.InsertFrames(this, nsnull, prevOverflowFrames);
+      ReParentChildListStyle(presContext, frames, this);
+    }
+  }
+}
+
 //////////////////////////////////////////////////////////////////////
 
 nsIFrame*
diff --git a/layout/generic/nsInlineFrame.h b/layout/generic/nsInlineFrame.h
index 1a613cf4a10..6feedcec7de 100644
--- a/layout/generic/nsInlineFrame.h
+++ b/layout/generic/nsInlineFrame.h
@@ -123,6 +123,8 @@ public:
 
   virtual PRBool CanContinueTextRun() const;
 
+  virtual void PullOverflowsFromPrevInFlow();
+
   // Take all of the frames away from this frame. The caller is
   // presumed to keep them alive.
   void StealAllFrames() {
@@ -222,6 +224,8 @@ public:
                     const nsHTMLReflowState& aReflowState,
                     nsReflowStatus& aStatus);
 
+  virtual void PullOverflowsFromPrevInFlow();
+
   // Take frames starting at aFrame until the end of the frame-list
   // away from this frame. The caller is presumed to keep them alive.
   void StealFramesFrom(nsIFrame* aFrame);