Bug 162695

Summary:	StringView should not delete the StringImpl it is viewing.
Product:	WebKit	Reporter:	Mark Lam <mark.lam>
Component:	Web Template Framework	Assignee:	Mark Lam <mark.lam>
Status:	RESOLVED INVALID
Severity:	Normal	CC:	darin, ddkilzer
Priority:	P2
Version:	WebKit Local Build
Hardware:	Unspecified
OS:	Unspecified

Description Mark Lam 2016-09-28 11:27:37 PDT

Currently, StringView uses a UnderlyingString that starts with a refCount of 1 independent of how many references to the underlying StringImpl exists.  In the StringView destructor, it then decrements its UnderlyingString refCount, and if that refCount is now 0, it proceeds to delete the referenced StringImpl even if the StringImpl's refCount is non-zero.  As a result, this prematurely frees the StringImpl that other code is still expecting to be alive.

Comment 1 Mark Lam 2016-09-28 11:32:56 PDT

To clarify, this issue only manifests when CHECK_STRINGVIEW_LIFETIME is enabled.

Comment 2 Mark Lam 2016-09-28 11:36:54 PDT

Hmmm ... I'm wrong.  Deleting the UnderlyingString should not delete the underlying StringImpl.  I'll dig a little further.

Comment 3 Mark Lam 2016-09-28 11:54:42 PDT

I misread the code.  This is not the issue I'm seeing.