Avoid use-after-free in QXcbConnection::initializeScreens()

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=86b8c5c3f32c2457
Last-Update: 2020-11-23

Gbp-Pq: Name xcb_screens_uaf.patch

qtbase-opensource-src (5.15.2+dfsg-13) unstable; urgency=medium

  [ Lu YaNing ]
  * Backport upstream patch to fix recursion crash when calling
    setStyleSheet with `qproperty-styleSheet`: fix_recursion_crash.diff.

  [ Dmitry Shachnev ]
  * Backport upstream patch to treat MYSQL_FIELD as read-only, to fix issues
    with MariaDB server 10.6 (closes: #999595).
  * Update symbols files from buildds’ and the current build logs.
  * Bump Standards-Version to 4.6.0, no changes needed.

[dgit import unpatched qtbase-opensource-src 5.15.2+dfsg-13]

Import qtbase-opensource-src_5.15.2+dfsg-13.debian.tar.xz

[dgit import tarball qtbase-opensource-src 5.15.2+dfsg-13 qtbase-opensource-src_5.15.2+dfsg-13.debian.tar.xz]

Import qtbase-opensource-src_5.15.2+dfsg.orig.tar.xz

[dgit import orig qtbase-opensource-src_5.15.2+dfsg.orig.tar.xz]