The documentation says:
The mapping will have the same open mode as the file (read and/or
write), except when using MapPrivateOption, in which case it is always
possible to write to the mapped memory.
So obey it.
This may cause high memory use by copying data we already have. This may
be important because applications may want to memory-map resources which
they intentionally didn't compress because those resources are
large. Later commits will implement some workarounds.
Fixes: QTBUG-124608
Pick-to: 6.7 6.6 6.5
Change-Id: I6979d02a7395405cbf23fffd17c8f03baf0ec00d
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
39e156e639