QImageReader: check allocation limit for minimum 32 bpp

Also, as a driveby, add an environment variable so the limit can be
changed at runtime.

[ChangeLog][QtGui][QImageReader] When checking allocation limit during
image reading, the memory requirements are now calculated for a
minimum of 32 bits per pixel, since Qt will typically convert an image
to that depth when it is used in GUI. This means that the effective
allocation limit is significantly smaller when reading 1 bpp and 8 bpp
images.

Change-Id: If1b204d413973b0975eea531e29c260fdcec931d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 8ce36938569841020daf9dc23e41438b06e0ee53)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

0 files changed, 0 insertions, 0 deletions