gmain: drop redundant using_pidfd field from GChildWatchSource

It's redundant, which leads to impossible code like:

   if (child_watch_source->using_pidfd)
     {
       if (child_watch_source->poll.fd >= 0)
         close (child_watch_source->poll.fd);

1 files changed, 11 insertions, 11 deletions

diff --git a/glib/gmain.c b/glib/gmain.c
index 6ba6fa02e..524a1bad9 100644
--- a/glib/gmain.c
+++ b/glib/gmain.c
@@ -374,11 +374,11 @@ struct _GChildWatchSource
 {
   GSource     source;
   GPid        pid;
-  /* @poll is always used on Windows, and used on Unix iff @using_pidfd is set: */
+  /* @poll is always used on Windows.
+   * On Unix, poll.fd will be negative if PIDFD is unavailable. */
   GPollFD     poll;
 #ifndef G_OS_WIN32
   gboolean child_maybe_exited;
-  gboolean using_pidfd;
 #endif /* G_OS_WIN32 */
 };
 
@@ -5514,7 +5514,10 @@ g_child_watch_prepare (GSource *source,
 
     child_watch_source = (GChildWatchSource *) source;
 
-    return !child_watch_source->using_pidfd && g_atomic_int_get (&child_watch_source->child_maybe_exited);
+    if (child_watch_source->poll.fd >= 0)
+      return FALSE;
+
+    return g_atomic_int_get (&child_watch_source->child_maybe_exited);
   }
 #endif /* G_OS_WIN32 */
 }
@@ -5531,7 +5534,7 @@ g_child_watch_check (GSource *source)
   child_exited = child_watch_source->poll.revents & G_IO_IN;
 #else /* G_OS_WIN32 */
 #ifdef HAVE_PIDFD
-  if (child_watch_source->using_pidfd)
+  if (child_watch_source->poll.fd >= 0)
     {
       child_exited = child_watch_source->poll.revents & G_IO_IN;
       return child_exited;
@@ -5549,10 +5552,9 @@ g_child_watch_finalize (GSource *source)
 #ifndef G_OS_WIN32
   GChildWatchSource *child_watch_source = (GChildWatchSource *) source;
 
-  if (child_watch_source->using_pidfd)
+  if (child_watch_source->poll.fd >= 0)
     {
-      if (child_watch_source->poll.fd >= 0)
-        close (child_watch_source->poll.fd);
+      close (child_watch_source->poll.fd);
       return;
     }
 
@@ -5900,7 +5902,7 @@ g_child_watch_dispatch (GSource    *source,
     wait_status = -1;
 
 #ifdef HAVE_PIDFD
-    if (child_watch_source->using_pidfd)
+    if (child_watch_source->poll.fd >= 0)
       {
         siginfo_t child_info = {
           0,
@@ -6085,17 +6087,15 @@ g_child_watch_source_new (GPid pid)
    * better than SIGCHLD.
    */
   child_watch_source->poll.fd = (int) syscall (SYS_pidfd_open, pid, 0);
-  errsv = errno;
 
   if (child_watch_source->poll.fd >= 0)
     {
-      child_watch_source->using_pidfd = TRUE;
       child_watch_source->poll.events = G_IO_IN;
       g_source_add_poll (source, &child_watch_source->poll);
-
       return source;
     }
 
+  errsv = errno;
   g_debug ("pidfd_open(%" G_PID_FORMAT ") failed with error: %s",
            pid, g_strerror (errsv));
   /* Fall through; likely the kernel isn’t new enough to support pidfd_open() */