From 1e843489e3b72d7ac06cac0fce9e4bb9c689ec7b Mon Sep 17 00:00:00 2001
From: Mats Palmgren <matspal@gmail.com>
Date: Wed, 23 May 2012 17:27:15 +0200
Subject: [PATCH] Bug 756241.  r=roc

---
 layout/generic/nsTextFrame.h         |  4 ++-
 layout/generic/nsTextFrameThebes.cpp | 37 ++++++++++++++++++++--------
 2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/layout/generic/nsTextFrame.h b/layout/generic/nsTextFrame.h
index 98e18bf308c..30180e889a0 100644
--- a/layout/generic/nsTextFrame.h
+++ b/layout/generic/nsTextFrame.h
@@ -385,7 +385,9 @@ public:
 
   void ClearTextRuns() {
     ClearTextRun(nsnull, nsTextFrame::eInflated);
-    ClearTextRun(nsnull, nsTextFrame::eNotInflated);
+    if (HasFontSizeInflation()) {
+      ClearTextRun(nsnull, nsTextFrame::eNotInflated);
+    }
   }
 
   // Get the DOM content range mapped by this frame after excluding
diff --git a/layout/generic/nsTextFrameThebes.cpp b/layout/generic/nsTextFrameThebes.cpp
index cc887b60351..24878e8f718 100644
--- a/layout/generic/nsTextFrameThebes.cpp
+++ b/layout/generic/nsTextFrameThebes.cpp
@@ -406,8 +406,9 @@ ClearAllTextRunReferences(nsTextFrame* aFrame, gfxTextRun* aTextRun,
   bool found = aStartContinuation == aFrame;
   while (aFrame) {
     NS_ASSERTION(aFrame->GetType() == nsGkAtoms::textFrame, "Bad frame");
-    if (!aFrame->RemoveTextRun(aTextRun))
+    if (!aFrame->RemoveTextRun(aTextRun)) {
       break;
+    }
     aFrame = static_cast<nsTextFrame*>(aFrame->GetNextContinuation());
   }
   NS_POSTCONDITION(!found || aStartContinuation, "how did we find null?");
@@ -4211,13 +4212,16 @@ void
 nsTextFrame::ClearTextRun(nsTextFrame* aStartContinuation,
                           TextRunType aWhichTextRun)
 {
-  // save textrun because ClearAllTextRunReferences may clear ours
   gfxTextRun* textRun = GetTextRun(aWhichTextRun);
-
-  if (!textRun)
+  if (!textRun) {
     return;
+  }
 
+  DebugOnly<bool> checkmTextrun = textRun == mTextRun;
   UnhookTextRunFromFrames(textRun, aStartContinuation);
+  MOZ_ASSERT(checkmTextrun ? !mTextRun
+                           : !Properties().Get(UninflatedTextRunProperty()));
+
   // see comments in BuildTextRunForFrames...
 //  if (textRun->GetFlags() & gfxFontGroup::TEXT_IS_PERSISTENT) {
 //    NS_ERROR("Shouldn't reach here for now...");
@@ -6919,7 +6923,7 @@ HasSoftHyphenBefore(const nsTextFragment* aFrag, gfxTextRun* aTextRun,
 }
 
 static void
-RemoveInFlows(nsIFrame* aFrame, nsIFrame* aFirstToNotRemove)
+RemoveInFlows(nsTextFrame* aFrame, nsTextFrame* aFirstToNotRemove)
 {
   NS_PRECONDITION(aFrame != aFirstToNotRemove, "This will go very badly");
   // We have to be careful here, because some RemoveFrame implementations
@@ -6944,6 +6948,21 @@ RemoveInFlows(nsIFrame* aFrame, nsIFrame* aFirstToNotRemove)
   
   nsIFrame* prevContinuation = aFrame->GetPrevContinuation();
   nsIFrame* lastRemoved = aFirstToNotRemove->GetPrevContinuation();
+  nsIFrame* parent = aFrame->GetParent();
+  nsBlockFrame* parentBlock = nsLayoutUtils::GetAsBlock(parent);
+  if (!parentBlock) {
+    // Clear the text run on the first frame we'll remove to make sure none of
+    // the frames we keep shares its text run.  We need to do this now, before
+    // we unlink the frames to remove from the flow, because DestroyFrom calls
+    // ClearTextRuns() and that will start at the first frame with the text
+    // run and walk the continuations.  We only need to care about the first
+    // and last frames we remove since text runs are contiguous.
+    aFrame->ClearTextRuns();
+    if (aFrame != lastRemoved) {
+      // Clear the text run on the last frame we'll remove for the same reason.
+      static_cast<nsTextFrame*>(lastRemoved)->ClearTextRuns();
+    }
+  }
 
   prevContinuation->SetNextInFlow(aFirstToNotRemove);
   aFirstToNotRemove->SetPrevInFlow(prevContinuation);
@@ -6951,16 +6970,14 @@ RemoveInFlows(nsIFrame* aFrame, nsIFrame* aFirstToNotRemove)
   aFrame->SetPrevInFlow(nsnull);
   lastRemoved->SetNextInFlow(nsnull);
 
-  nsIFrame *parent = aFrame->GetParent();
-  nsBlockFrame *parentBlock = nsLayoutUtils::GetAsBlock(parent);
   if (parentBlock) {
     // Manually call DoRemoveFrame so we can tell it that we're
     // removing empty frames; this will keep it from blowing away
     // text runs.
     parentBlock->DoRemoveFrame(aFrame, nsBlockFrame::FRAMES_ARE_EMPTY);
   } else {
-    // Just remove it normally; use the nextBidi list to avoid
-    // posting new reflows.
+    // Just remove it normally; use kNoReflowPrincipalList to avoid posting
+    // new reflows.
     parent->RemoveFrame(nsIFrame::kNoReflowPrincipalList, aFrame);
   }
 }
@@ -7031,7 +7048,7 @@ nsTextFrame::SetLength(PRInt32 aLength, nsLineLayout* aLineLayout,
 
   // Note that in the process we may end up removing some frames from
   // the flow if they end up empty.
-  nsIFrame *framesToRemove = nsnull;
+  nsTextFrame* framesToRemove = nsnull;
   while (f && f->mContentOffset < end) {
     f->mContentOffset = end;
     if (f->GetTextRun(nsTextFrame::eInflated) != mTextRun) {