[1.18] Update subtree: libglnx 2026-06-18 - #6752

We can't easily assert this without triggering warnings from tools like
valgrind by doing an invalid operation on a closed fd, so we only check
this when under `-m undefined`.

Originally contributed to GLib 2.76 in GNOME/glib@b3934133
"gstdio: Add g_clear_fd() and g_autofd". The implementation in GLib used
g_fsync() as a portable thing that we can do with a fd, but that
function is newer than our minimum GLib version, and libglnx isn't
portable to non-Unix anyway, so use fnctl() instead.

Signed-off-by: Simon McVittie <[email protected]>

We document glnx_close_fd as preserving errno, so let's assert that it
really does. There are three code paths we need to exercise:

1. fd < 0: glnx_close_fd does nothing, successfully
2. fd >= 0 and close() succeeds
3. fd >= 0 and close() fails

The first two are easy, but it's difficult to make close() fail on-demand
with only valid code. close(2) documents EIO, but it's difficult to
cause an I/O error on-demand. Similarly, close(2) documents ENOSPC
and EDQUOT on NFS, but we are unlikely to have a full NFS filesystem
available during testing.

Instead, we can trigger a failure via the programming error of passing a
fd to glnx_close_fd that was already closed, which makes close(2) fail
with EBADF. In older libglnx, we wouldn't have been able to test this
because it caused an assertion failure, but in GLib and new libglnx it
only causes a critical warning, which we can catch and ignore.

See also GLib commit GNOME/glib@f1f711dc "tests: Test EBADF and errno
handling when closing fds". GLib doesn't have a 1:1 equivalent of
glnx_close_fd as public API, but an internal version is used to
implement g_autofd.

Signed-off-by: Simon McVittie <[email protected]>

When building with newer GLib with GLIB_VERSION_MAX_ALLOWED set
to < 2.76 in downstream, g_clear_fd is marked deprecated in
libglnx and triggers deprecation warnings at each call site.

This forwards to g_clear_fd while silencing deprecation warnings for
Glib >= 2.76

Fixes: https://gitlab.gnome.org/GNOME/libglnx/-/issues/7

backports: Wrap g_clear_fd to silence deprecations for newer Glib

Closes flatpak#7

See merge request GNOME/libglnx!72

backports, local-alloc: Provide a backport of g_autofd

See merge request GNOME/libglnx!68

This makes it possible to use a standard dependency('libglnx') call in a
parent project when libglnx is used as a subproject.

fdio: Add support for name_to_handle_at

See merge request GNOME/libglnx!70

build: Add meson.override_dependency('libglnx', libglnx_dep)

See merge request GNOME/libglnx!77

It takes a callback which gets called every time we try to open the next
segment of the path. This allows implementing more specific and advanced
use cases to be implemented without adding more complexity to the chase
algorithm itself.

We found that there is a common use case where we need to get a
subdirectory (potentially multiple levels) which might not exist yet.
Adding another flag for this to GlnxChaseFlags is what systemd has done,
but creating a directory takes a mode, so the flag creates directories
with a fixed mode. This approach instead takes the mode as argument.

chase: Add glnx_chase_and_mkdirat

See merge request GNOME/libglnx!76

* backports, local-alloc: Provide a backport of g_autofd
* build: Add meson.override_dependency('libglnx', libglnx_dep)
* fdio: Add support for name_to_handle_at
* chase: Add glnx_chase_and_mkdirat

Signed-off-by: Sebastian Wick <[email protected]>