Bug 1377648 - Fix HTMLSummaryElement::IsSummary() on removing the element

* Use inFlowFrame to check the target frame is summary and its parent is details
* Check summary frame instead of summary element on removing the summary

Tag #1375

1 files changed, 6 insertions, 0 deletions

diff --git a/layout/generic/DetailsFrame.h b/layout/generic/DetailsFrame.h
index 1eb4ea87be..4ae177f16f 100644
--- a/layout/generic/DetailsFrame.h
+++ b/layout/generic/DetailsFrame.h
@@ -54,6 +54,12 @@ public:
 
   void AppendAnonymousContentTo(nsTArray<nsIContent*>& aElements,
                                 uint32_t aFilter) override;
+  // Returns true if |aSummaryFrame| is the main summary (i.e. the first child
+  // of this details frame).
+  // This function is used when the summary element is removed from the parent
+  // details element since at that moment the summary element has been already
+  // removed from the details element children.
+  bool HasMainSummaryFrame(nsIFrame* aSummaryFrame);
 
 private:
   nsCOMPtr<nsIContent> mDefaultSummary;