Bug 1878753 - Fix focus gets incorrectly cleared by PresShell::FixUpFocus if the focus is on area element r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D200950

layout/base/PresShell.cpp

@@ -13,6 +13,7 @@
 #include "mozilla/dom/ElementBinding.h"
 #include "mozilla/dom/LargestContentfulPaint.h"
 #include "mozilla/dom/PerformanceMainThread.h"
+#include "mozilla/dom/HTMLAreaElement.h"
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/AutoRestore.h"
@@ -1483,6 +1484,14 @@ bool PresShell::FixUpFocus() {
     return false;
   }
 
+  // If focus target is an area element with one or more shapes that are
+  // focusable areas.
+  if (auto* area = HTMLAreaElement::FromNode(currentFocus)) {
+    if (nsFocusManager::IsAreaElementFocusable(*area)) {
+      return false;
+    }
+  }
+
   nsIFrame* f = currentFocus->GetPrimaryFrame();
   if (f && f->IsFocusable()) {
     return false;