[PATCH] Fix invalid pointer return with QGridLayout::itemAt(-1)

QGridLayout::takeAt() and QLayoutItem *itemAt() only check the upper bound.
If the index < 0, these function will return invalid pointer.

Fixes: QTBUG-91261
Pick-to: 5.15 6.0 6.1
Change-Id: Idfb9fb6228b9707f817353b04974da16205a835c
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Gbp-Pq: Name fix-invalid-pointer-return-with-QGridLayout.diff

adjust QMimeDatabase implementation

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=0cbbba2aa5b47224
Last-Update: 2021-06-12

When multiple globs match, and the result from magic sniffing is
unrelated to any of those globs, globs have priority and one of them
should be picked up.

Gbp-Pq: Name mime_globs.diff

fix allocated memory of QByteArray returned by QIODevice::readLine

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=6485b6d45ad165cf
Last-Update: 2021-02-20

Gbp-Pq: Name qiodevice_readline_memory.diff

include <limits> to fix some GCC 11 build issues

Origin: upstream, commits:
 https://code.qt.io/cgit/qt/qtbase.git/commit/?id=813a928c7c3cf986
 https://code.qt.io/cgit/qt/qtbase.git/commit/?id=9c56d4da2ff631a8
Last-Update: 2021-01-26

Gbp-Pq: Name gcc_11_limits.diff

QNAM: work around QObject finicky orphan cleanup details

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=0807f16eb407eaf8
Last-Update: 2021-01-26

Gbp-Pq: Name qnam_connect_memory_leak.diff

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]