[webkit-changes] [WebKit/WebKit] 21dd74: Improve overflow handing ergonomics in JSStringJoi...

[Commit Queue]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 21dd74926ee09f152bff236747b4621a05f0983b
      https://github.com/WebKit/WebKit/commit/21dd74926ee09f152bff236747b4621a05f0983b
  Author: Mark Lam <mark.lam at apple.com>
  Date:   2024-01-05 (Fri, 05 Jan 2024)

  Changed paths:
    M Source/JavaScriptCore/runtime/JSStringJoiner.cpp
    M Source/JavaScriptCore/runtime/JSStringJoiner.h
    M Source/WTF/wtf/Vector.h

  Log Message:
  -----------
  Improve overflow handing ergonomics in JSStringJoiner::append().
https://bugs.webkit.org/show_bug.cgi?id=267111
rdar://120389377

Reviewed by Justin Michaud.

Currently, JSStringJoiner::append() appends to its m_string Vector.  As a result, if an overflow
is imminent, it crashes.  We change the code to use tryAppend() instead and remember if an
overflow was detected instead.  If so, JSStringJoiner::join() can throw an OutOfMemory error later.

* Source/JavaScriptCore/runtime/JSStringJoiner.cpp:
(JSC::JSStringJoiner::joinSlow):
* Source/JavaScriptCore/runtime/JSStringJoiner.h:
(JSC::JSStringJoiner::join):
(JSC::JSStringJoiner::append):
(JSC::JSStringJoiner::append8Bit):
(JSC::JSStringJoiner::appendEmptyString):
* Source/WTF/wtf/Vector.h:
(WTF::Vector::tryAppend):

Canonical link: https://commits.webkit.org/272688@main