Bug 1348851 - Part 1. Use new block when better selection isn't found. r=masayuki

This is a kind of regression of bug 1088054 part 6.  If new block doesn't have child node, GetLastEditableChild will return null after landing bug 1088054. So, we should use new block when GetLastEditableChild returns null.

MozReview-Commit-ID: Gzt1Xp3Sl47
***
P1

MozReview-Commit-ID: 8LVp5qGnme4

--HG--
extra : rebase_source : f0ed76b65517168b6b11edf96164b3e596038fc1

editor/libeditor/HTMLEditRules.cpp

@@ -7301,14 +7301,17 @@ HTMLEditRules::PinSelectionToNewBlock(Selection* aSelection)
     return NS_OK;
   }
 
+  if (NS_WARN_IF(!mNewBlock)) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
   // get the (collapsed) selection location
-  nsCOMPtr<nsIDOMNode> selNode, temp;
+  nsCOMPtr<nsIDOMNode> selNode;
   int32_t selOffset;
   nsresult rv =
     EditorBase::GetStartNodeAndOffset(aSelection,
                                       getter_AddRefs(selNode), &selOffset);
   NS_ENSURE_SUCCESS(rv, rv);
-  temp = selNode;
 
   // use ranges and sRangeHelper to compare sel point to new block
   nsCOMPtr<nsINode> node = do_QueryInterface(selNode);
@@ -7318,24 +7321,23 @@ HTMLEditRules::PinSelectionToNewBlock(Selection* aSelection)
   NS_ENSURE_SUCCESS(rv, rv);
   rv = range->SetEnd(selNode, selOffset);
   NS_ENSURE_SUCCESS(rv, rv);
-  nsCOMPtr<nsIContent> block = mNewBlock.get();
-  NS_ENSURE_TRUE(block, NS_ERROR_NO_INTERFACE);
   bool nodeBefore, nodeAfter;
-  rv = nsRange::CompareNodeToRange(block, range, &nodeBefore, &nodeAfter);
+  rv = nsRange::CompareNodeToRange(mNewBlock, range, &nodeBefore, &nodeAfter);
   NS_ENSURE_SUCCESS(rv, rv);
 
   if (nodeBefore && nodeAfter) {
     return NS_OK;  // selection is inside block
   } else if (nodeBefore) {
     // selection is after block.  put at end of block.
-    nsCOMPtr<nsIDOMNode> tmp = GetAsDOMNode(mNewBlock);
     NS_ENSURE_STATE(mHTMLEditor);
-    tmp = GetAsDOMNode(mHTMLEditor->GetLastEditableChild(*block));
+    nsCOMPtr<nsINode> tmp = mHTMLEditor->GetLastEditableChild(*mNewBlock);
+    if (!tmp) {
+      tmp = mNewBlock;
+    }
     uint32_t endPoint;
     if (EditorBase::IsTextNode(tmp) ||
         mHTMLEditor->IsContainer(tmp)) {
-      rv = EditorBase::GetLengthOfDOMNode(tmp, endPoint);
-      NS_ENSURE_SUCCESS(rv, rv);
+      endPoint = tmp->Length();
     } else {
       tmp = EditorBase::GetNodeLocation(tmp, (int32_t*)&endPoint);
       endPoint++;  // want to be after this node
@@ -7343,9 +7345,11 @@ HTMLEditRules::PinSelectionToNewBlock(Selection* aSelection)
     return aSelection->Collapse(tmp, (int32_t)endPoint);
   } else {
     // selection is before block.  put at start of block.
-    nsCOMPtr<nsIDOMNode> tmp = GetAsDOMNode(mNewBlock);
     NS_ENSURE_STATE(mHTMLEditor);
-    tmp = GetAsDOMNode(mHTMLEditor->GetFirstEditableChild(*block));
+    nsCOMPtr<nsINode> tmp = mHTMLEditor->GetFirstEditableChild(*mNewBlock);
+    if (!tmp) {
+      tmp = mNewBlock;
+    }
     int32_t offset;
     if (EditorBase::IsTextNode(tmp) ||
         mHTMLEditor->IsContainer(tmp)) {