Improve 'alarm' implementation on MS-Windows.

 src/w32proc.c (alarm) [HAVE_SETITIMER]: Be more conformant to the expected
 return results.
 [!HAVE_SETITIMER]: Behave as the previous version that didn't
 support timers.

1 files changed, 7 insertions, 3 deletions

diff --git a/src/w32proc.c b/src/w32proc.c
index 159d6e00957..b0881c25d6c 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -669,15 +669,19 @@ setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 int
 alarm (int seconds)
 {
-  struct itimerval new_values;
+#ifdef HAVE_SETITIMER
+  struct itimerval new_values, old_values;
 
   new_values.it_value.tv_sec = seconds;
   new_values.it_value.tv_usec = 0;
   new_values.it_interval.tv_sec = new_values.it_interval.tv_usec = 0;
 
-  setitimer (ITIMER_REAL, &new_values, NULL);
-
+  if (setitimer (ITIMER_REAL, &new_values, &old_values) < 0)
+    return 0;
+  return old_values.it_value.tv_sec;
+#else
   return seconds;
+#endif
 }
 
 /* Defined in <process.h> which conflicts with the local copy */