Bug 1574852 - part 67-9: Make next early return-style code work without `AutoTrackDOMPoint` r=m_kato

The next simple case is using early-return style and does not refer modified
`firstRangeStart` nor `firstRangeEnd` so that it can do same thing without
`AutoTrackDOMPoint`.

Then, there is remaining the complicated case.  We cannot split it anymore.

Note that we should not split `HandleDeleteNonCollapsedSelection()` anymore
because as you know, it does not make sense.  It checks only first range
and consider how to treat all ranges.  We should split it after we investigate
deeper with writing new WPT.

Differential Revision: https://phabricator.services.mozilla.com/D44459

--HG--
extra : moz-landing-system : lando

editor/libeditor/HTMLEditRules.cpp

@@ -3181,6 +3181,9 @@ EditActionResult HTMLEditRules::HandleDeleteNonCollapsedSelection(
       HTMLEditor::GetBlock(*firstRangeStart.GetContainer());
   RefPtr<Element> rightBlock =
       HTMLEditor::GetBlock(*firstRangeEnd.GetContainer());
+  if (NS_WARN_IF(!leftBlock) || NS_WARN_IF(!rightBlock)) {
+    return EditActionHandled(NS_ERROR_FAILURE);  // XXX "handled"??
+  }
 
   // XXX This is also odd.  We do we simply use
   //     `DeleteSelectionWithTransaction()` only when **first** range is in
@@ -3205,65 +3208,57 @@ EditActionResult HTMLEditRules::HandleDeleteNonCollapsedSelection(
     return EditActionHandled(rv);
   }
 
+  // Deleting across blocks.
+
+  // If left block and right block are adjuscent siblings and they are same
+  // type of elements, we can merge them after deleting the selected contents.
+  // MOOSE: this could conceivably screw up a table.. fix me.
+  if (leftBlock->GetParentNode() == rightBlock->GetParentNode() &&
+      HTMLEditorRef().AreNodesSameType(*leftBlock, *rightBlock) &&
+      // XXX What's special about these three types of block?
+      (leftBlock->IsHTMLElement(nsGkAtoms::p) ||
+       HTMLEditUtils::IsListItem(leftBlock) ||
+       HTMLEditUtils::IsHeader(*leftBlock))) {
+    // First delete the selection
+    nsresult rv = MOZ_KnownLive(HTMLEditorRef())
+                      .DeleteSelectionWithTransaction(aDirectionAndAmount,
+                                                      aStripWrappers);
+    if (NS_WARN_IF(!CanHandleEditAction())) {
+      return EditActionHandled(NS_ERROR_EDITOR_DESTROYED);
+    }
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return EditActionHandled(rv);
+    }
+    // Join blocks
+    EditorDOMPoint atFirstChildOfTheLastRightNode =
+        MOZ_KnownLive(HTMLEditorRef())
+            .JoinNodesDeepWithTransaction(*leftBlock, *rightBlock);
+    if (NS_WARN_IF(!CanHandleEditAction())) {
+      return EditActionHandled(NS_ERROR_EDITOR_DESTROYED);
+    }
+    if (NS_WARN_IF(!atFirstChildOfTheLastRightNode.IsSet())) {
+      return EditActionHandled(NS_ERROR_FAILURE);
+    }
+    // Fix up selection
+    ErrorResult error;
+    SelectionRefPtr()->Collapse(atFirstChildOfTheLastRightNode, error);
+    if (NS_WARN_IF(!CanHandleEditAction())) {
+      error.SuppressException();
+      return EditActionHandled(NS_ERROR_EDITOR_DESTROYED);
+    }
+    NS_WARNING_ASSERTION(!error.Failed(), "Selection::Collapse() failed");
+    return EditActionHandled(error.StealNSResult());
+  }
+
+  // Otherwise, delete every nodes in all ranges, then, clean up something.
   EditActionResult result(NS_OK);
   result.MarkAsHandled();
   {
-    // Track location of where we are deleting
-    // NOTE: Right now, firstRangeStart.mOffset and firstRangeEnd.mOffset
-    //       are fixed so that we keep compatibility with older code which
-    //       treated offset directly.
     AutoTrackDOMPoint startTracker(HTMLEditorRef().RangeUpdaterRef(),
                                    &firstRangeStart);
     AutoTrackDOMPoint endTracker(HTMLEditorRef().RangeUpdaterRef(),
                                  &firstRangeEnd);
 
-    // Deleting across blocks.  Are the blocks of same type?
-    if (NS_WARN_IF(!leftBlock) || NS_WARN_IF(!rightBlock)) {
-      return result.SetResult(NS_ERROR_FAILURE);
-    }
-
-    // Are the blocks siblings?
-    nsCOMPtr<nsINode> leftBlockParent = leftBlock->GetParentNode();
-    nsCOMPtr<nsINode> rightBlockParent = rightBlock->GetParentNode();
-
-    // MOOSE: this could conceivably screw up a table.. fix me.
-    if (leftBlockParent == rightBlockParent &&
-        HTMLEditorRef().AreNodesSameType(*leftBlock, *rightBlock) &&
-        // XXX What's special about these three types of block?
-        (leftBlock->IsHTMLElement(nsGkAtoms::p) ||
-         HTMLEditUtils::IsListItem(leftBlock) ||
-         HTMLEditUtils::IsHeader(*leftBlock))) {
-      // First delete the selection
-      nsresult rv = MOZ_KnownLive(HTMLEditorRef())
-                        .DeleteSelectionWithTransaction(aDirectionAndAmount,
-                                                        aStripWrappers);
-      if (NS_WARN_IF(!CanHandleEditAction())) {
-        return result.SetResult(NS_ERROR_EDITOR_DESTROYED);
-      }
-      if (NS_WARN_IF(NS_FAILED(rv))) {
-        return result.SetResult(rv);
-      }
-      // Join blocks
-      EditorDOMPoint atFirstChildOfTheLastRightNode =
-          MOZ_KnownLive(HTMLEditorRef())
-              .JoinNodesDeepWithTransaction(*leftBlock, *rightBlock);
-      if (NS_WARN_IF(!CanHandleEditAction())) {
-        return result.SetResult(NS_ERROR_EDITOR_DESTROYED);
-      }
-      if (NS_WARN_IF(!atFirstChildOfTheLastRightNode.IsSet())) {
-        return result.SetResult(NS_ERROR_FAILURE);
-      }
-      // Fix up selection
-      ErrorResult error;
-      SelectionRefPtr()->Collapse(atFirstChildOfTheLastRightNode, error);
-      if (NS_WARN_IF(!CanHandleEditAction())) {
-        error.SuppressException();
-        return result.SetResult(NS_ERROR_EDITOR_DESTROYED);
-      }
-      NS_WARNING_ASSERTION(!error.Failed(), "Selection::Collapse() failed");
-      return result.SetResult(error.StealNSResult());
-    }
-
     // Else blocks not same type, or not siblings.  Delete everything
     // except table elements.
     bool join = true;