[webkit-changes] [WebKit/WebKit] 331064: Web Inspector: Deeply nested async stack traces ar...

[Patrick Angle]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 33106442561e29aec6760903d306bb78c3eee2fc
      https://github.com/WebKit/WebKit/commit/33106442561e29aec6760903d306bb78c3eee2fc
  Author: Patrick Angle <pangle at apple.com>
  Date:   2023-05-22 (Mon, 22 May 2023)

  Changed paths:
    M LayoutTests/inspector/debugger/async-stack-trace-truncate-expected.txt
    M LayoutTests/inspector/debugger/async-stack-trace-truncate.html
    M Source/JavaScriptCore/inspector/AsyncStackTrace.cpp
    M Source/JavaScriptCore/inspector/ScriptCallStack.cpp
    M Source/JavaScriptCore/inspector/ScriptCallStack.h

  Log Message:
  -----------
  Web Inspector: Deeply nested async stack traces are not fully truncated
https://bugs.webkit.org/show_bug.cgi?id=254244
rdar://105900359

Reviewed by Yusuke Suzuki.

As of 252630 at main, ScriptCallStack holds a reference to its parent AsyncStackTrace to enable providing async stack
traces in places where previously the async context was being lost. However when this was added, the truncation
functionality used to ensure that AsyncStackTrace did not create an infinitely nested set of objects did not take the
new reference into account. In practice, we should break that relationship any time we are removing the parent of the
AsyncStackTrace. This allows us to correctly release ownership of AsyncStackTraces as we nest deeper, then preventing us
from recursing during their deconstruction later.

* LayoutTests/inspector/debugger/async-stack-trace-truncate-expected.txt:
* LayoutTests/inspector/debugger/async-stack-trace-truncate.html:
- Add test case that creates a nested set of AsyncStackTrace/ScriptCallStack that will exceed the size of the stack if
not correctly truncated.

* Source/JavaScriptCore/inspector/AsyncStackTrace.cpp:
(Inspector::AsyncStackTrace::remove):
Remove the ScriptCallStack's parent at the same time we remove the AsyncStackTrace's parent.

* Source/JavaScriptCore/inspector/ScriptCallStack.cpp:
(Inspector::ScriptCallStack::removeParentStackTrace):
* Source/JavaScriptCore/inspector/ScriptCallStack.h:

Originally-landed-as: 259548.467 at safari-7615-branch (69eae63cd374). rdar://105900359
Canonical link: https://commits.webkit.org/264354@main