Bug 1460509 - part 15: Make HTMLEditRules::WillRemoveAbsolutePosition() return NS_ERROR_EDITOR_DESTROYED if it causes destroying the editor r=m_kato

MozReview-Commit-ID: DXzdtPQ01lo

--HG--
extra : rebase_source : 1fa36a1195aa7a6b5d891f83659af155b5bb16c0

editor/libeditor/HTMLEditRules.cpp

@@ -10232,11 +10232,21 @@ HTMLEditRules::WillRemoveAbsolutePosition(bool* aCancel,
     return NS_ERROR_FAILURE;
   }
 
-  AutoSelectionRestorer selectionRestorer(&SelectionRef(), &HTMLEditorRef());
+  {
+    AutoSelectionRestorer selectionRestorer(&SelectionRef(), &HTMLEditorRef());
 
-  nsresult rv = HTMLEditorRef().SetPositionToAbsoluteOrStatic(*element, false);
+    nsresult rv = HTMLEditorRef().SetPositionToAbsoluteOrStatic(*element, false);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
+    if (NS_WARN_IF(!CanHandleEditAction())) {
-    return rv;
+      return NS_ERROR_EDITOR_DESTROYED;
+    }
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  // Restoring Selection might cause destroying the HTML editor.
+  if (NS_WARN_IF(!CanHandleEditAction())) {
+    return NS_ERROR_EDITOR_DESTROYED;
   }
   return NS_OK;
 }

editor/libeditor/HTMLEditRules.h

@@ -259,7 +259,18 @@ protected:
   nsresult WillAlign(const nsAString& aAlignType,
                      bool* aCancel, bool* aHandled);
   nsresult WillAbsolutePosition(bool* aCancel, bool* aHandled);
-  nsresult WillRemoveAbsolutePosition(bool* aCancel, bool* aHandled);
+
+  /**
+   * Called before changing absolute positioned element to static positioned.
+   * This method actually changes the position property of nearest absolute
+   * positioned element.  Therefore, this might cause destroying the HTML
+   * editor.
+   *
+   * @param aCancel             Returns true if the operation is canceled.
+   * @param aHandled            Returns true if the edit action is handled.
+   */
+  MOZ_MUST_USE nsresult
+  WillRemoveAbsolutePosition(bool* aCancel, bool* aHandled);
 
   /**
    * Called before changing z-index.