[webkit-changes] [WebKit/WebKit] c19a62: Fix use-after-free memory error

[Matthieu Dubet]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: c19a6292aab1bafc47e52b1bfb4341a06472ef75
      https://github.com/WebKit/WebKit/commit/c19a6292aab1bafc47e52b1bfb4341a06472ef75
  Author: Matthieu Dubet <m_dubet at apple.com>
  Date:   2022-10-28 (Fri, 28 Oct 2022)

  Changed paths:
    M Source/WebCore/platform/text/TextFlags.cpp

  Log Message:
  -----------
  Fix use-after-free memory error
rdar://101637166

Reviewed by Brent Fulgham.

The previous code was creating a temporary vector
which was passed to Span. Because Span doesn't own
memory, the vector was (potentially) released at
the end of the lambda function.

With this patch, a reference to the vector stored in
the HashMap is given to Span<> (we don't use a temporary anymore),
which is live for at least the whole duration of the
computeFontFeatureSettingsFromVariants function.

* Source/WebCore/platform/text/TextFlags.cpp:
(WebCore::computeFeatureSettingsFromVariants):

Canonical link: https://commits.webkit.org/256089@main