This is a crash introduced with http://trac.webkit.org/changeset/169500.
When we compute the editor state information we don't need to compute the charactersAroundPosition if we are not in editable content.
Created attachment 232737 [details]
Attachment 232737 [details] did not pass style-queue:
ERROR: Source/WebKit2/WebProcess/WebPage/WebPage.cpp:718: Missing space before ( in if( [whitespace/parens] 
Total errors found: 1 in 4 files
If any of these errors are false positives, please file a bug against check-webkit-style.
I've already fixed the style issue.
Comment on attachment 232737 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=232737&action=review
> + if (index >= maxCharacters)
> + break;
Shouldn't this be after "characters[index++] = characterString[i];".
You may want to change the for() loop into a while loop. Having a for() loop that breaks into the flow tends to add complexity.
Committed revision 169728.