OpenFile portal: do not use O_PATH fds
requested to merge asturmlechner/qtbase:asturmlechner/QTBUG-113143-OpenFile-portal-no-use-O_PATH-fds into kde/5.15
Using O_PATH requires correctly specifying whether the fd is writable or not. Stating that the fd is writable without it actually being writable results into rejection on xdg-desktop-portal side. Other implementations like xdg-open or gtk have also moved away from O_PATH fds so this will make a matching implementation and avoid possible rejections from xdp.
Fixes: QTBUG-113143 Pick-to: 6.5 5.15 Change-Id: Icc171752d73ee091282b7c655f71da3cb59179b1 Reviewed-by: Thiago Macieira thiago.macieira@intel.com (cherry picked from commit 03cbcba7)
Note: Stale upstream 5.15 codereview, again. @grulich: Maybe you could prod Qt company once more? See also: https://bugreports.qt.io/browse/QTBUG-113143