Confirm no crash when selecting all text with mixed editability.
| "\n"
| <span>
|   "\n   "
|   <span>
|     <span>
|       contenteditable="true"
|       "12345"
|   "\n   "
|   <span>
|     contenteditable="true"
|     id="test"
|     <#selection-caret>
|   "\n"
| "\n"