boot-time: Make it work on Adélie Linux

[Bruno Haible]

Adélie Linux is one of the worst distros I have seen in the last few years.
(The 'live' installer CD-ROM does not work. The package search website has an
incomplete list of packages. Missing dependencies between essential packages.
Lots of silly behaviour everywhere.)

Nevertheless, the 'boot-time' module should work on this platform.
Done through this patch (which makes get_boot_time() look at the time stamp
of the /var/run/utmp file):


2023-11-16  Bruno Haible  <bruno@clisp.org>

        boot-time: Make it work on Adélie Linux.
        * lib/boot-time.c (get_boot_time_uncached): Invoke Linux fallbacks also
        on Linux systems that have neither <utmp.h> nor <utmpx.h>.

diff --git a/lib/boot-time.c b/lib/boot-time.c
index fe5b5b88c8..70329c3aa5 100644
--- a/lib/boot-time.c
+++ b/lib/boot-time.c
@@ -203,7 +203,14 @@ get_boot_time_uncached (struct timespec *p_boot_time)
     }
 #  endif
 
-# else /* old FreeBSD, OpenBSD, native Windows */
+# else /* Adélie Linux, old FreeBSD, OpenBSD, native Windows */
+
+#  if defined __linux__ && !defined __ANDROID__
+  /* Workaround for Adélie Linux:  */
+  get_linux_boot_time_fallback (&found_boot_time);
+  if (found_boot_time.tv_sec == 0)
+    get_linux_boot_time_final_fallback (&found_boot_time);
+#  endif
 
 #  if defined __OpenBSD__
   /* Workaround for OpenBSD:  */