StringBuilder::append(StringBuilder& other) always uses other.characters() to access the characters to append. This should be changed to use characters8() or characters16() as appropriate.
Created attachment 168523 [details] Patch
Comment on attachment 168523 [details] Patch Attachment 168523 [details] did not pass mac-ews (mac): Output: http://queues.webkit.org/results/14292122 New failing tests: fast/css/transform-inline-style.html editing/execCommand/5458246.html fast/css/remove-shorthand.html fast/dom/HTMLMeterElement/meter-element-with-child-crash.html editing/execCommand/create-list-with-hr.html editing/pasteboard/input-field-1.html editing/inserting/insert-images-in-pre-x-crash.html fast/backgrounds/repeat/parsing-background-repeat.html editing/pasteboard/4806874.html fast/css/transform-inline-style-remove.html editing/pasteboard/paste-line-endings-001.html fast/backgrounds/background-shorthand-with-backgroundSize-style.html fast/css/background-position-serialize.html editing/execCommand/insert-ordered-list.html editing/execCommand/infinite-recursion-computeRectForRepaint.html fast/dom/background-shorthand-csstext.html fast/css/shorthand-mismatched-list-crash.html
Created attachment 168541 [details] Fix for test failures Added missing "else".
Committed r131250: <http://trac.webkit.org/changeset/131250>
Comment on attachment 168541 [details] Fix for test failures Silly me. I checked characters8() and characters16(), and did not pay much attention to the actual code...