Removing text styles in CSS mode was potentially removing too much if the styles were added in HTML mode

The fix creates a span element that will carry the inline styles and class of the HTML element to be removed, if any.
b=202037, r=kaie, sr=dmose

editor/idl/nsIEditor.idl

@@ -373,6 +373,21 @@ interface nsIEditor  : nsISupports
   void removeAttribute(in nsIDOMElement aElement, 
                        in AString aAttribute);
 
+  /**
+   * cloneAttribute() copies the attribute from the source node to
+   * the destination node and delete those not in the source.
+   *
+   * The supplied nodes MUST BE ELEMENTS (most callers are working with nodes)
+   * @param aAttribute    the name of the attribute to copy
+   * @param aDestNode     the destination element to operate on
+   * @param aSourceNode   the source element to copy attributes from
+   * @exception NS_ERROR_NULL_POINTER at least one of the nodes is null
+   * @exception NS_ERROR_NO_INTERFACE at least one of the nodes is not an
+   *                                  element
+   */
+  void cloneAttribute(in AString aAttribute,
+                      in nsIDOMNode aDestNode, in nsIDOMNode aSourceNode);
+
   /**
    * cloneAttributes() is similar to nsIDOMNode::cloneNode(),
    *   it assures the attribute nodes of the destination are identical

editor/libeditor/base/nsEditor.cpp

@@ -2223,6 +2223,36 @@ nsEditor::EndOperation()
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsEditor::CloneAttribute(const nsAString & aAttribute,
+                         nsIDOMNode *aDestNode, nsIDOMNode *aSourceNode)
+{
+  nsresult rv = NS_OK;
+
+  if (!aDestNode || !aSourceNode)
+    return NS_ERROR_NULL_POINTER;
+
+  nsCOMPtr<nsIDOMElement> destElement = do_QueryInterface(aDestNode);
+  nsCOMPtr<nsIDOMElement> sourceElement = do_QueryInterface(aSourceNode);
+  if (!destElement || !sourceElement)
+    return NS_ERROR_NO_INTERFACE;
+
+  nsAutoString attrValue;
+  PRBool isAttrSet;
+  rv = GetAttributeValue(sourceElement,
+                         aAttribute,
+                         attrValue,
+                         &isAttrSet);
+  if (NS_FAILED(rv))
+    return rv;
+  if (isAttrSet)
+    rv = SetAttribute(destElement, aAttribute, attrValue);
+  else
+    rv = RemoveAttribute(destElement, aAttribute);
+
+  return rv;
+}
+
 // Objects must be DOM elements
 NS_IMETHODIMP
 nsEditor::CloneAttributes(nsIDOMNode *aDestNode, nsIDOMNode *aSourceNode)

editor/libeditor/html/nsHTMLEditorStyle.cpp

@@ -691,6 +691,27 @@ nsresult nsHTMLEditor::RemoveStyleInside(nsIDOMNode *aNode,
     // remove any matching inlinestyles entirely
     if (!aAttribute || aAttribute->IsEmpty())
     {
+      NS_NAMED_LITERAL_STRING(styleAttr, "style");
+      NS_NAMED_LITERAL_STRING(classAttr, "class");
+      PRBool hasStyleAttr = HasAttr(aNode, &styleAttr);
+      PRBool hasClassAtrr = HasAttr(aNode, &classAttr);
+      if (hasStyleAttr || hasClassAtrr) {
+        // aNode carries inline styles or a class attribute so we can't
+        // just remove the element... We need to create above the element
+        // a span that will carry those styles or class, then we can delete
+        // the node.
+        nsCOMPtr<nsIDOMNode> spanNode;
+        res = InsertContainerAbove(aNode, address_of(spanNode),
+                                   NS_LITERAL_STRING("span"));
+        if (NS_FAILED(res))
+          return res;
+        res = CloneAttribute(styleAttr, spanNode, aNode);
+        if (NS_FAILED(res))
+          return res;
+        res = CloneAttribute(classAttr, spanNode, aNode);
+        if (NS_FAILED(res))
+          return res;
+      }
       res = RemoveContainer(aNode);
     }
     // otherwise we just want to eliminate the attribute