(xnanosleep): Work around bug in Linux-2.6.8.1's

nanosleep whereby it fails without setting errno upon being resumed
after being suspended.

diff --git a/lib/xnanosleep.c b/lib/xnanosleep.c
index 8aa5e8a..5ac9f2e 100644 (file)
--- a/lib/xnanosleep.c
+++ b/lib/xnanosleep.c
@@ -123,9 +123,16 @@ xnanosleep (double seconds)
          ts_sleep.tv_nsec = BILLION - 1;
        }
 
+      /* Linux-2.6.8.1's nanosleep returns -1, but doesn't set errno
+        when resumed after being suspended.  Earlier versions would
+        set errno to EINTR.  nanosleep from linux-2.6.10, as well as
+        implementations by (all?) other vendors, doesn't return -1
+        in that case;  either it continues sleeping (if time remains)
+        or it returns zero (if the wake-up time has passed).  */
+      errno = 0;
       if (nanosleep (&ts_sleep, NULL) == 0)
        break;
-      if (errno != EINTR)
+      if (errno != EINTR && errno != 0)
        return -1;
 
       if (NANOSLEEP_BUG_WORKAROUND)