From 2b21f8f65daf68f19bf9b15e5205656d03ca879f Mon Sep 17 00:00:00 2001 From: Timothy Nikkel Date: Wed, 6 Jul 2016 16:55:17 -0500 Subject: [PATCH] Bug 1277123. Only clear the containing block clip when entering an out of flow with an unknown clip. r=mattwoodrow The content clip is still valid, as we are only descending into content descendants. The clip for content descendants that the root scroll frame creates so content doesn't overflow (visually or for event handling) the main scrollbar can get cleared otherwise. --- layout/generic/nsFrame.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp index 3afcde7a64d5..6e2d70055a39 100644 --- a/layout/generic/nsFrame.cpp +++ b/layout/generic/nsFrame.cpp @@ -2807,7 +2807,7 @@ nsIFrame::BuildDisplayListForChild(nsDisplayListBuilder* aBuilder, // then we won't have stored clip data for it. We can just clear the clip // instead since we know we won't render anything, and the inner out-of-flow // frame will setup the correct clip for itself. - clipState.Clear(); + clipState.SetClipForContainingBlockDescendants(nullptr); clipState.SetScrollClipForContainingBlockDescendants(nullptr); }