Newly inserted line rows may have the "lineNumber" property set (e.g. when inserting via a native Undo), thus interfering with the current numeration. We should also delete the "lineNumber" from line rows on DOMNodeRemoved event as a double defense.
Created attachment 84854 [details] Patch
Comment on attachment 84854 [details] Patch Test?
Comment on attachment 84854 [details] Patch Clearing flags on attachment: 84854 Committed r80632: <http://trac.webkit.org/changeset/80632>
All reviewed patches have been landed. Closing bug.