[PATCH] mktime & nanosleep: make sure SIGALRM is not blocked

[Mike Frysinger]

Some systems might have SIGALRM blocked when running configure.  If that
is the case, the nanosleep() test will sleep for practically ever as the
signal generated by alarm() is never delivered.  As such, we should make
sure to unblock SIGALRM before running any tests.

This crops up from time to time on Linux systems (google for "SIGALRM
blocked" for examples).

Not sure if the m4 files need to depend on some other signal checks ...

Signed-off-by: Mike Frysinger <address@hidden>
---
 m4/mktime.m4    |    6 +++++-
 m4/nanosleep.m4 |    6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/m4/mktime.m4 b/m4/mktime.m4
index 1e926e8..f261265 100644
--- a/m4/mktime.m4
+++ b/m4/mktime.m4
@@ -1,4 +1,4 @@
-# serial 15
+# serial 16
 dnl Copyright (C) 2002-2003, 2005-2007, 2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -170,6 +170,10 @@ main ()
   /* This test makes some buggy mktime implementations loop.
      Give up after 60 seconds; a mktime slower than that
      isn't worth using anyway.  */
+  sigset_t set;
+  sigemptyset (&set);
+  sigaddset (&set, SIGALRM);
+  sigprocmask (SIG_UNBLOCK, &set, NULL);
   alarm (60);
 
   for (;;)
diff --git a/m4/nanosleep.m4 b/m4/nanosleep.m4
index 7f08744..d727e19 100644
--- a/m4/nanosleep.m4
+++ b/m4/nanosleep.m4
@@ -1,4 +1,4 @@
-# serial 27
+# serial 28
 
 dnl From Jim Meyering.
 dnl Check for the nanosleep function.
@@ -69,6 +69,10 @@ AC_DEFUN([gl_FUNC_NANOSLEEP],
          static struct timespec ts_sleep;
          static struct timespec ts_remaining;
          static struct sigaction act;
+         static sigset_t set;
+         sigemptyset (&set);
+         sigaddset (&set, SIGALRM);
+         sigprocmask (SIG_UNBLOCK, &set, NULL);
          if (! nanosleep)
            return 1;
          act.sa_handler = check_for_SIGALRM;
-- 
1.6.3