Adjust insertion point when listifying unordered list items

third_party/WebKit/Source/core/editing/commands/InsertListCommand.cpp

 /*
  * Copyright (C) 2006, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 590 matching lines @@
   }
 
   document().updateStyleAndLayoutIgnorePendingStylesheets();
 
   // Insert the list at a position visually equivalent to start of the
   // paragraph that is being moved into the list.
   // Try to avoid inserting it somewhere where it will be surrounded by
   // inline ancestors of start, since it is easier for editing to produce
   // clean markup when inline elements are pushed down as far as possible.
   Position insertionPos(mostBackwardCaretPosition(startPos));
+  // Also avoid the temporary <span> element created by 'unlistifyParagraph'.
+  // This element can be selected by mostBackwardCaretPosition when startPor
+  // points to a element with previous siblings or ancestors with siblings.
+  // |-A
+  // | |-B
+  // | +-C (insertion point)
+  // |   |-D (*)
+  if (isHTMLSpanElement(insertionPos.anchorNode()))

[yosin_UTC9, 2017/03/21 05:37:20]

Could you use Position::computeContainerNode() instead of
Position::anchorNode()?
For PositonType::{Before,After}Anchor, Pos::anchorNode() isn't what we want to
use.

[jfernandez, 2017/03/24 01:57:55]

Done.

+    insertionPos = Position::inParentBeforeNode(*insertionPos.anchorNode());
   // Also avoid the containing list item.
   Node* const listChild = enclosingListChild(insertionPos.anchorNode());
   if (isHTMLLIElement(listChild))
     insertionPos = Position::inParentBeforeNode(*listChild);
 
   HTMLElement* listElement = createHTMLElement(document(), listTag);
   insertNodeAt(listElement, insertionPos, editingState);
   if (editingState->isAborted())
     return;
   HTMLLIElement* listItemElement = HTMLLIElement::create(document());
@@ skipping 42 matching lines @@
       endOfParagraph(validPos, CanSkipOverEditingBoundary);
   moveParagraph(start, end, VisiblePosition::beforeNode(placeholder),
                 editingState, PreserveSelection);
 }
 
 DEFINE_TRACE(InsertListCommand) {
   CompositeEditCommand::trace(visitor);
 }
 
 }  // namespace blink