Bug 1460509 - part 31: Make HTMLEditRules::GetInlineStyles() return NS_ERROR_EDITOR_DESTROYED if it causes destroying the editor r=m_kato

MozReview-Commit-ID: 3Nk1gBttuwM

--HG--
extra : rebase_source : b9e0d63683407d9e5440157309cb61d213524223

editor/libeditor/HTMLEditRules.cpp

@@ -8516,6 +8516,9 @@ HTMLEditRules::GetInlineStyles(nsINode* aNode,
       isSet = CSSEditUtils::IsCSSEquivalentToHTMLInlineStyleSet(
                 aNode, aStyleCache[j].tag, aStyleCache[j].attr, outValue,
                 CSSEditUtils::eComputed);
+      if (NS_WARN_IF(!CanHandleEditAction())) {
+        return NS_ERROR_EDITOR_DESTROYED;
+      }
     }
     if (isSet) {
       aStyleCache[j].mPresent = true;
@@ -8556,7 +8559,7 @@ HTMLEditRules::ReapplyCachedStyles()
   InitStyleCacheArray(styleAtInsertionPoint);
   nsresult rv = GetInlineStyles(selNode, styleAtInsertionPoint);
   if (NS_WARN_IF(NS_FAILED(rv))) {
-    return NS_OK;
+    return rv == NS_ERROR_EDITOR_DESTROYED ? NS_ERROR_EDITOR_DESTROYED : NS_OK;
   }
 
   for (size_t i = 0; i < SIZE_STYLE_TABLE; ++i) {

editor/libeditor/HTMLEditRules.h

@@ -778,10 +778,11 @@ protected:
 
   /**
    * GetInlineStyles() retrieves the style of aNode and modifies each item of
-   * aStyleCache.
+   * aStyleCache.  This might cause flushing layout at retrieving computed
+   * values of CSS properties.
    */
-  nsresult GetInlineStyles(nsINode* aNode,
-                           StyleCache aStyleCache[SIZE_STYLE_TABLE]);
+  MOZ_MUST_USE nsresult
+  GetInlineStyles(nsINode* aNode, StyleCache aStyleCache[SIZE_STYLE_TABLE]);
 
 protected:
   HTMLEditor* mHTMLEditor;