Signed-off-by: Philip Withnall <withnall@endlessm.com>

Backport !1620 “gvariant: Ensure GVS.depth is initialised” to glib-2-64

See merge request !1621

When byteswapping the depth was accidentally left uninitialised.

Coverity CID: #1430636
Signed-off-by: Philip Withnall <withnall@endlessm.com>

Backport !1617 “Ensure g_subprocess_communicate_async() never blocks” to glib-2-64

See merge request !1618

Alexander Larsson authored Aug 17, 2020 and Philip Withnall committed Aug 17, 2020

It turns out that our async write operation implementation is broken
on non-O_NONBLOCK pipes, because the default async write
implementation calls write() after poll() said there were some
space. However, the semantics of pipes is that unless O_NONBLOCK is set
then the write *will* block if the passed in write count is larger than
the available space.

This caused a deadlock in #2182
due to the loop-back of the app stdout to the parent, but even without such
a deadlock it is a problem that we may block the mainloop at all.

In the particular case of g_subprocess_communicate() we have full
control of the pipes after starting the app, so it is safe to enable
O_NONBLOCK (i.e. we can ensure all the code using the fd after this can handle
non-blocking mode).

This fixes #2182

Backport !1607 “meson: Don't use gnulib for printf on iOS” to glib-2-64

See merge request !1608

Nirbheek Chauhan authored Aug 06, 2020 and Philip Withnall committed Aug 06, 2020

iOS and tvOS use the same printf family as macOS, and these all have
been available on macOS for a long time.

Closes #1868

Backport !1563 “gdesktopappinfo: Fix unnecessarily copied and leaked URI list” to glib-2-64

See merge request !1565

Felix Riemann authored Jul 04, 2020 and Philip Withnall committed Jul 06, 2020

When an app is spawned using g_desktop_app_info_launch_uris_with_spawn
it will expand the various token in the app's commandline with the
URIs of the files to open. The expand_macro() function that is used for
this advances the pointer to the URI list to show up to which entries
it used.

To not loose the pointer to the list head a duplicate of the URI list
was actually passed to expand_macro(). However, it's not necessary to
create a copy of the URI list for that as expand_macro() will only
change which element the pointer will point to.

This behaviour actually caused the duplicated list to be leaked as the
the list pointer is NULL once all URIs are used up by expand_macro()
and thus nothing was freed at the end of the function.

Backport !1517 “GWin32RegistryKey: Move assertions” to glib-2-64

See merge request !1520

Backport !1468 “glib-compile-resources: Fix exporting on Visual Studio” to glib-2-64

See merge request !1519

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Backport !1544 “Resolve "calling malloc in fork child is undefined-behaviour"” to glib-2-64

See merge request !1547

Allocate a working buffer before calling `fork()` to avoid calling
`malloc()` in the async-signal-safe context between `fork()` and
`exec()`, where it’s not safe to use.

In this case, the buffer is used to assemble a wrapper around `argv` so
it can be run under `/bin/sh`.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Fixes: #2140

Allocate a working buffer before calling `fork()` to avoid calling
`malloc()` in the async-signal-safe context between `fork()` and
`exec()`, where it’s not safe to use.

In this case, the buffer is used to assemble elements from `PATH` with
the binary from `argv[0]` to try executing them.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #2140

Query the environment before calling `fork()` so that it doesn’t have to
be called in the async-signal-safe context between `fork()` and
`exec()`.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #2140

They’re not safe to call in an async-signal-safe context on Linux.
`sysconf()` is safe to call on FreeBSD and OpenBSD (at least), so
continue doing that.

This will reduce performance in the (already low performance) fallback
case where `/proc` is inaccessible to a forked process on Linux, while
spawning a subprocess.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #2140

Use the error handling infrastructure which already exists for other
failures in the async-signal-safe context.

`g_assert()` is unlikely to have caused problems in practice because it
is only async-signal-unsafe when the assertion condition fails.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #2140

While `g_ascii_isdigit()` *is* currently async-signal-safe, it’s going
to be hard to remember to keep it that way if the implementation changes
in future.

It seems more robust to just reimplement it here, given that it’s not
much code.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #2140

Use normal `close()` instead, which is guaranteed to be
async-signal-safe.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #2140

Functions called between `fork()` and `exec()` have to be
async-signal-safe.

Add a comment to each function which is called in that context, and
`FIXME` comments to the non-async-signal-safe functions which end up
being called as leaves of the call graph.

The following commits will fix those `FIXME`s.

See `man 7 signal-safety`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #2140

In almost all cases, rewording the documentation/comments made things
more specific and a little clearer.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

See: !1544 (comment 846645)

Backport !1522 “meson: Fix gnulib printf checks” to glib-2-64

See merge request !1523

Nirbheek Chauhan authored Jun 08, 2020 and Philip Withnall committed Jun 08, 2020

Some typos, and accidental usage of the strings `'true'` / `'false'`
instead of the booleans `true` / `false`.

LRN authored Jun 04, 2020 and Philip Withnall committed Jun 05, 2020

While these assertions look right at the first glance,
they actually crash the program. That's because GObject
insists on initializing all construct-only properties
to their default values, which results in
g_win32_registry_key_set_property() being called multiple
times with NULL string, once for each unset property.

If "path" is actually set by the caller, a subsequent
call to set "path-utf16" to NULL will fail an assertion,
since absolute_path is already non-NULL.

With assertions moved the set-to-NULL calls bail out before
an assertion is made.

Chun-wei Fan authored Apr 29, 2020 and Philip Withnall committed Jun 05, 2020

Have the generated .c code decorate the prototypes with "G_MODULE_EXPORT"
instead of "extern" when --internal is not being used, so that we also
export the symbols from the generated code on Visual Studio-style
compilers.  If --internal is used, we decorate the prototypes with
"G_GNUC_INTERNAL", as we did before.

Note that since the generated .c code does not attempt to include the
generated headers (if one is also generated), the gnerated headers are
still generated as they were before.

Backport !1504 “win32 gpoll: Fix wait for at least one thread to return” to glib-2-64

See merge request !1507

majordaw authored May 20, 2020 and Philip Withnall committed May 22, 2020

When timeout grater than 0 in g_poll function, the WaitForMultipleObjects
call will wait for all the threads to return, but when only one thread
got an event the others will sleep until the timeout elapses, and causes
a stall. Triggering the stop event in g_poll in this case is useless as
it is triggered when all the threads where already signaled or timed-out.

Closes: #2107

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Backport !1493 “meson: Remove stray ], in O_DIRECTORY check” to glib-2-64

See merge request !1495

Chris Packham authored May 13, 2020 and Philip Withnall committed May 19, 2020

A stray ], was leftover from the autotools -> meson conversion. Remove
it.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>

Backport !1439 “Fix stpcpy() detection“ to glib-2-64

See merge request !1501

Martin Storsjö authored Mar 31, 2020 and Philip Withnall committed May 19, 2020

See https://github.com/mesonbuild/meson/issues/3672 and
https://github.com/mesonbuild/meson/issues/5628 for explanations
of cases where meson misdetects functions due to clang builtins (that
always are available, regardless of whether the platform actually
provides them).

The same also happens on GCC 10, which added support for __has_builtin.

Backport !1440 -Wformat-nonliteral fixes to glib-2-64

See merge request !1470

Backport !1448 memory monitor test dependency fixes to glib-2-64

See merge request !1471