pidfd's are dup()ed twice

[arrowd]

Operating System

Any

XDG Desktop Portal version

Git

Current Behavior

Not sure if this is a bug and hurts something, but I noticed that pidfd's obtained from the D-Bus GetConnectionCredentials API gets dup()ed twice:

• First in xdp-app-info.c:xdp_connection_get_pidfd() before returning
• Then in xdp-app-info.c:xdp_app_info_initialize() when constructing priv

It feels like the second dup() should be unnecessary?

[swick]

The fd we get in xdp_connection_get_pidfd we need to take from a GUnixFDList which doesn't allow us to steal a specific fd from that list, so we do have to dup it. It is closed by the autofd. Then in XdpAppInfo initialization we dup the fd again which is then owned by the object and is closed when it gets disposed. So it all works out, but we do not mark the fd's as FD_CLOEXEC and the last dup could be avoided. Created #1680 for that.