From cf0319510266f78392252dc3eb6e4681c0c78738 Mon Sep 17 00:00:00 2001
From: Alexander Surkov <surkov.alexander@gmail.com>
Date: Mon, 1 Feb 2016 17:05:45 -0500
Subject: [PATCH] Bug 1220502 - ignore not visible text nodes for tree update,
 r=tbsaunde, roc

---
 accessible/base/NotificationController.h | 11 +++++++++--
 layout/generic/nsTextFrame.cpp           |  4 +++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/accessible/base/NotificationController.h b/accessible/base/NotificationController.h
index 946b7964f0c..ab106fc00c1 100644
--- a/accessible/base/NotificationController.h
+++ b/accessible/base/NotificationController.h
@@ -122,8 +122,15 @@ public:
    */
   inline void ScheduleTextUpdate(nsIContent* aTextNode)
   {
-    if (mTextHash.PutEntry(aTextNode))
-      ScheduleProcessing();
+    // Make sure we are not called with a node that is not in the DOM tree or
+    // not visible.
+    MOZ_ASSERT(aTextNode->GetParentNode(), "A text node is not in DOM");
+    MOZ_ASSERT(aTextNode->GetPrimaryFrame(), "A text node doesn't have a frame");
+    MOZ_ASSERT(aTextNode->GetPrimaryFrame()->StyleVisibility()->IsVisible(),
+               "A text node is not visible");
+
+    mTextHash.PutEntry(aTextNode);
+    ScheduleProcessing();
   }
 
   /**
diff --git a/layout/generic/nsTextFrame.cpp b/layout/generic/nsTextFrame.cpp
index 8010ecac81c..8ebe07807c2 100644
--- a/layout/generic/nsTextFrame.cpp
+++ b/layout/generic/nsTextFrame.cpp
@@ -8498,7 +8498,9 @@ nsTextFrame::ReflowText(nsLineLayout& aLineLayout, nscoord aAvailableWidth,
 
 #ifdef ACCESSIBILITY
   // Schedule the update of accessible tree since rendered text might be changed.
-  ReflowTextA11yNotifier(presContext, mContent);
+  if (StyleVisibility()->IsVisible()) {
+    ReflowTextA11yNotifier(presContext, mContent);
+  }
 #endif
 
   /////////////////////////////////////////////////////////////////////