Commit f4df1632 authored by Magnus Melin's avatar Magnus Melin
Browse files

Bug 1869195 - Fix crash in [@ mozilla::PresShell::GetRootScrollFrame]. r=emilio, a=dmeehan 

Differential Revision: https://phabricator.services.mozilla.com/D196021
parent 2557ef36

layout/base/PresShell.cpp

+12 −3
Original line number Diff line number Diff line
@@ -2480,17 +2480,26 @@ PresShell::CompleteMove(bool aForward, bool aExtend) { 
// end implementations nsISelectionController



nsIFrame* PresShell::GetRootScrollFrame() const {

  if (!mFrameConstructor) {

    return nullptr;

  }

  nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();

  // Ensure root frame is a viewport frame

  if (!rootFrame || !rootFrame->IsViewportFrame()) return nullptr;

  if (!rootFrame || !rootFrame->IsViewportFrame()) {

    return nullptr;

  }

  nsIFrame* theFrame = rootFrame->PrincipalChildList().FirstChild();

  if (!theFrame || !theFrame->IsScrollFrame()) return nullptr;

  if (!theFrame || !theFrame->IsScrollFrame()) {

    return nullptr;

  }

  return theFrame;

}



nsIScrollableFrame* PresShell::GetRootScrollFrameAsScrollable() const {

  nsIFrame* frame = GetRootScrollFrame();

  if (!frame) return nullptr;

  if (!frame) {

    return nullptr;

  }

  nsIScrollableFrame* scrollableFrame = do_QueryFrame(frame);

  NS_ASSERTION(scrollableFrame,

               "All scroll frames must implement nsIScrollableFrame");