[webkit-changes] [WebKit/WebKit] 79f077: Speculative fix for crash mitigation in JSModuleRe...

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  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 79f077301b073479201ec6d29ac564fe2c6738e4
      https://github.com/WebKit/WebKit/commit/79f077301b073479201ec6d29ac564fe2c6738e4
  Author: Yijia Huang <yijia_huang at apple.com>
  Date:   2023-04-04 (Tue, 04 Apr 2023)

  Changed paths:
    M Source/JavaScriptCore/runtime/JSModuleRecord.cpp

  Log Message:
  -----------
  Speculative fix for crash mitigation in JSModuleRecord::instantiateDeclarations
https://bugs.webkit.org/show_bug.cgi?id=255013
rdar://107634974

Reviewed by Mark Lam.

This is a speculative fix to mitigate a crash in JSModuleRecord::instantiateDeclarations
which is due to an undefined imported module. However, the existing implementation
should already handle the undefined case by throwing and catching an exception when
encountering an undefined JSValue. This patch ensures that the target pointer will not
have the undefined value. If it does, we'll throw an exception.

* Source/JavaScriptCore/runtime/JSModuleRecord.cpp:
(JSC::JSModuleRecord::instantiateDeclarations):

Canonical link: https://commits.webkit.org/262608@main