Bug 1407305 - Part 4: Avoid using GetChildAt() in EditorBase::GetNextNode(); r=masayuki

editor/libeditor/EditorBase.cpp

@@ -3313,6 +3313,7 @@ EditorBase::GetPriorNode(nsINode* aParentNode,
 nsIContent*
 EditorBase::GetNextNode(nsINode* aParentNode,
                         int32_t aOffset,
+                        nsINode* aChildAtOffset,
                         bool aEditableNode,
                         bool aNoBlockCrossing)
 {
@@ -3327,15 +3328,16 @@ EditorBase::GetNextNode(nsINode* aParentNode,
   }
 
   // look at the child at 'aOffset'
-  nsIContent* child = aParentNode->GetChildAt(aOffset);
-  if (child) {
-    if (aNoBlockCrossing && IsBlockNode(child)) {
-      return child;
+  if (aChildAtOffset) {
+    if (aNoBlockCrossing && IsBlockNode(aChildAtOffset)) {
+      MOZ_ASSERT(aChildAtOffset->IsContent());
+      return aChildAtOffset->AsContent();
     }
 
-    nsIContent* resultNode = GetLeftmostChild(child, aNoBlockCrossing);
+    nsIContent* resultNode = GetLeftmostChild(aChildAtOffset, aNoBlockCrossing);
     if (!resultNode) {
-      return child;
+      MOZ_ASSERT(aChildAtOffset->IsContent());
+      return aChildAtOffset->AsContent();
     }
 
     if (!IsDescendantOfEditorRoot(resultNode)) {
@@ -4660,7 +4662,7 @@ EditorBase::CreateTxnForDeleteRange(nsRange* aRangeToDelete,
   if (aAction == ePrevious) {
     selectedNode = GetPriorNode(node, offset, child, true);
   } else if (aAction == eNext) {
-    selectedNode = GetNextNode(node, offset, true);
+    selectedNode = GetNextNode(node, offset, child, true);
   }
 
   while (selectedNode &&

editor/libeditor/EditorBase.h

@@ -731,6 +731,7 @@ public:
    */
   nsIContent* GetNextNode(nsINode* aParentNode,
                           int32_t aOffset,
+                          nsINode* aChildAtOffset,
                           bool aEditableNode,
                           bool aNoBlockCrossing = false);
 

editor/libeditor/HTMLEditRules.cpp

@@ -854,6 +854,7 @@ HTMLEditRules::GetAlignment(bool* aMixed,
                   selection->GetRangeAt(0)->GetStartContainer());
   OwningNonNull<nsINode> parent =
     *selection->GetRangeAt(0)->GetStartContainer();
+  nsIContent* child = selection->GetRangeAt(0)->GetChildAtStartOffset();
   int32_t offset = selection->GetRangeAt(0)->StartOffset();
 
   // Is the selection collapsed?
@@ -865,7 +866,7 @@ HTMLEditRules::GetAlignment(bool* aMixed,
     nodeToExamine = parent;
   } else if (parent->IsHTMLElement(nsGkAtoms::html) && offset == rootOffset) {
     // If we have selected the body, let's look at the first editable node
-    nodeToExamine = htmlEditor->GetNextNode(parent, offset, true);
+    nodeToExamine = htmlEditor->GetNextNode(parent, offset, child, true);
   } else {
     nsTArray<RefPtr<nsRange>> arrayOfRanges;
     GetPromotedRanges(selection, arrayOfRanges, EditAction::align);
@@ -5047,8 +5048,9 @@ HTMLEditRules::CheckForEmptyBlock(nsINode* aStartNode,
       if (aAction == nsIEditor::eNext || aAction == nsIEditor::eNextWord ||
           aAction == nsIEditor::eToEndOfLine) {
         // Move to the start of the next node, if any
-        nsCOMPtr<nsIContent> nextNode = htmlEditor->GetNextNode(blockParent,
-                                                                offset + 1, true);
+        nsINode* child = emptyBlock->GetNextSibling();
+        nsCOMPtr<nsIContent> nextNode =
+          htmlEditor->GetNextNode(blockParent, offset + 1, child, true);
         if (nextNode) {
           EditorDOMPoint pt = GetGoodSelPointForNode(*nextNode, aAction);
           nsresult rv = aSelection->Collapse(pt.node, pt.offset);

editor/libeditor/HTMLEditor.cpp

@@ -3946,7 +3946,8 @@ HTMLEditor::GetNextHTMLNode(nsINode* aParent,
                             nsINode* aChildAtOffset,
                             bool aNoBlockCrossing)
 {
-  nsIContent* content = GetNextNode(aParent, aOffset, true, aNoBlockCrossing);
+  nsIContent* content = GetNextNode(aParent, aOffset, aChildAtOffset,
+                                    true, aNoBlockCrossing);
   if (content && !IsDescendantOfEditorRoot(content)) {
     return nullptr;
   }