Bug 159063

Summary:	characterSubrange returns a single character range for an empty range
Product:	WebKit	Reporter:	Alexey Proskuryakov <ap>
Component:	HTML Editing	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	enrica, rniwa
Priority:	P2
Version:	Safari 9
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=159062

Description Alexey Proskuryakov 2016-06-23 11:06:08 PDT

As seen in bug 159062, DictionaryLookup::rangeAtHitTestResult returns a 1-character string when -[LULookupDefinitionModule tokenRangeForString:range:options:] returns (0, 0).

This seems like a pretty crazy bug deep inside editing code - why do we do this? We pass (0, 0) to TextIterator::subrange, then it goes to characterSubrange, and it becomes 1-character when routed through a character iterator.