From 1f5c67934f05d036de575c3d8172587fa6d398bc Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Thu, 16 Apr 2020 17:51:36 -0400 Subject: Bug 1343937 - Fix a crash in nsWrapperCache.h * Implement and use GetInFlowParent * Exempt scrollbar NAC from the new NAC semantics Tag #1375 --- layout/base/nsCSSFrameConstructor.cpp | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'layout/base/nsCSSFrameConstructor.cpp') diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp index a2dec55e1..e88b2d62c 100644 --- a/layout/base/nsCSSFrameConstructor.cpp +++ b/layout/base/nsCSSFrameConstructor.cpp @@ -10730,6 +10730,12 @@ nsCSSFrameConstructor::AddFCItemsForAnonymousContent( // first element that is not itself NAC (distinct from whether it happens // to be in a NAC subtree). // + // The one exception to all of this is scrollbar content, which we parent + // directly to the scrollframe. This is because the special-snowflake + // construction of scroll frames doesn't result in the placeholder frame + // being constructed until later, which means that GetInFlowParent() doesn't + // work right in the case of out-of-flow scrollframes. + // // To implement all this, we need to pass the correct parent style context // here because SetPrimaryFrame() may not have been called on the content // yet and thus ResolveStyleContext can't find it otherwise. @@ -10739,9 +10745,12 @@ nsCSSFrameConstructor::AddFCItemsForAnonymousContent( // to worry about anonymous boxes, which CorrectStyleParentFrame handles // for us. nsIFrame* inheritFrame = aFrame; - while (inheritFrame->GetContent()->IsNativeAnonymous()) { - inheritFrame = inheritFrame->GetParent(); + if (!content->IsNativeScrollbarContent()) { + while (inheritFrame->GetContent()->IsNativeAnonymous()) { + inheritFrame = inheritFrame->GetInFlowParent(); + } } + if (inheritFrame->GetType() == nsGkAtoms::canvasFrame) { // CorrectStyleParentFrame returns nullptr if the prospective parent is // the canvas frame, so avoid calling it in that situation. -- cgit v1.2.3