From 0d26e4514d7d6c90d2c5e35749c0b83121a66b77 Mon Sep 17 00:00:00 2001
From: "mtasaka@fedoraproject.org" <mtasaka@fedoraproject.org>
Date: Tue, 7 Feb 2017 16:40:52 +0900
Subject: [PATCH] misc: kill gcc warn_unused_result warnings

Remove misc warnings generated gcc -Wall with
"warning: ignoring return value of 'foo',
declared with attribute warn_unused_result".

For setuid() and fgets(), really check the returned value.
For system(), for now just use empty body to avoid this
warning. Note that casting the result to (void) does not
remove these warnings.
---
 driver/demo-Gtk.c      | 9 +++++++--
 hacks/glx/sonar-icmp.c | 2 +-
 hacks/glx/sonar.c      | 5 +++--
 hacks/recanim.c        | 6 +++++-
 4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/driver/demo-Gtk.c b/driver/demo-Gtk.c
index f5c4839..7c34846 100644
--- a/driver/demo-Gtk.c
+++ b/driver/demo-Gtk.c
@@ -4423,7 +4423,8 @@ kde_screensaver_active_p (void)
   FILE *p = popen ("dcop kdesktop KScreensaverIface isEnabled 2>/dev/null",
                    "r");
   char buf[255];
-  fgets (buf, sizeof(buf)-1, p);
+  if (!p) return False;
+  if (!fgets (buf, sizeof(buf)-1, p)) return False;
   pclose (p);
   if (!strcmp (buf, "true\n"))
     return True;
@@ -4434,7 +4435,11 @@ kde_screensaver_active_p (void)
 static void
 kill_kde_screensaver (void)
 {
-  system ("dcop kdesktop KScreensaverIface enable false");
+  /* Use empty body to kill warning from gcc -Wall with
+     "warning: ignoring return value of 'system',
+      declared with attribute warn_unused_result"
+  */
+  if (system ("dcop kdesktop KScreensaverIface enable false")) {}
 }
 
 
diff --git a/hacks/glx/sonar-icmp.c b/hacks/glx/sonar-icmp.c
index 8256270..26eb90d 100644
--- a/hacks/glx/sonar-icmp.c
+++ b/hacks/glx/sonar-icmp.c
@@ -1634,7 +1634,7 @@ sonar_init_ping (Display *dpy, char **error_ret, char **desc_ret,
     fprintf (stderr, "%s: unable to open icmp socket\n", progname);
 
   /* Disavow privs */
-  setuid(getuid());
+  if (setuid(getuid()) == -1) abort();
 
   pd->pid = getpid() & 0xFFFF;
   pd->seq = 0;
diff --git a/hacks/glx/sonar.c b/hacks/glx/sonar.c
index f3a4d9d..2c6ca5b 100644
--- a/hacks/glx/sonar.c
+++ b/hacks/glx/sonar.c
@@ -930,8 +930,9 @@ init_sensor (ModeInfo *mi)
     sp->ssd = sonar_init_ping (MI_DISPLAY (mi), &sp->error, &sp->desc,
                                ping_arg, ping_timeout, resolve_p, times_p,
                                debug_p);
-  else
-    setuid(getuid()); /* Disavow privs if not pinging. */
+  else {
+    if (setuid(getuid()) == -1) abort(); /* Disavow privs if not pinging. */
+  }
 
   sp->start_time = double_time ();  /* for error message timing */
 
diff --git a/hacks/recanim.c b/hacks/recanim.c
index 51379ed..a526c25 100644
--- a/hacks/recanim.c
+++ b/hacks/recanim.c
@@ -324,7 +324,11 @@ screenhack_record_anim_free (record_anim_state *st)
            " 2>&-",
            fn);
   fprintf (stderr, "%s: exec: %s\n", progname, cmd);
-  system (cmd);
+  /* Use empty body to kill warning from gcc -Wall with
+     "warning: ignoring return value of 'system',
+      declared with attribute warn_unused_result"
+  */
+  if (system (cmd)) {}
 
   if (stat (fn, &s))
     {
-- 
2.9.3