diff options
| -rw-r--r-- | dom/base/DOMIntersectionObserver.cpp | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/dom/base/DOMIntersectionObserver.cpp b/dom/base/DOMIntersectionObserver.cpp index 5798335b4..f5e59c2b9 100644 --- a/dom/base/DOMIntersectionObserver.cpp +++ b/dom/base/DOMIntersectionObserver.cpp @@ -269,17 +269,21 @@ DOMIntersectionObserver::Update(nsIDocument* aDocument, DOMHighResTimeStamp time root = mRoot; rootFrame = root->GetPrimaryFrame(); if (rootFrame) { + nsRect rootRectRelativeToRootFrame; if (rootFrame->GetType() == nsGkAtoms::scrollFrame) { + // rootRectRelativeToRootFrame should be the content rect of rootFrame, not including the scrollbars. nsIScrollableFrame* scrollFrame = do_QueryFrame(rootFrame); - rootRect = nsLayoutUtils::TransformFrameRectToAncestor( - rootFrame, - rootFrame->GetContentRectRelativeToSelf(), - scrollFrame->GetScrolledFrame()); + rootRectRelativeToRootFrame = scrollFrame->GetScrollPortRect(); } else { - rootRect = nsLayoutUtils::GetAllInFlowRectsUnion(rootFrame, - nsLayoutUtils::GetContainingBlockForClientRect(rootFrame), - nsLayoutUtils::RECTS_ACCOUNT_FOR_TRANSFORMS); + // rootRectRelativeToRootFrame should be the border rect of rootFrame. + rootRectRelativeToRootFrame = rootFrame->GetRectRelativeToSelf(); } + nsIFrame* containingBlock = + nsLayoutUtils::GetContainingBlockForClientRect(rootFrame); + rootRect = + nsLayoutUtils::TransformFrameRectToAncestor(rootFrame, + rootRectRelativeToRootFrame, + containingBlock); } } else { nsCOMPtr<nsIPresShell> presShell = aDocument->GetShell(); |