Cope with Unixes that don't have LOG_PERROR, like Solaris 10

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=39987Reviewed-by: Will Thompson <will.thompson@collabora.co.uk>

configure.ac

@@ -520,6 +520,11 @@ AC_CHECK_FUNC(gethostbyname,,[AC_CHECK_LIB(nsl,gethostbyname)])
 
 AC_CHECK_FUNCS(vsnprintf vasprintf nanosleep usleep setenv clearenv unsetenv socketpair getgrouplist fpathconf setrlimit poll setlocale localeconv strtoll strtoull)
 
+AC_CHECK_HEADERS([syslog.h])
+if test "x$ac_cv_header_syslog_h" = "xyes"; then
+  AC_CHECK_DECLS([LOG_PERROR], [], [], [[#include <syslog.h>]])
+fi
+
 #### Check for broken poll; taken from Glib's configure
 
 AC_MSG_CHECKING([for broken poll])

dbus/dbus-sysdeps-util-unix.c

@@ -422,11 +422,16 @@ _dbus_request_file_descriptor_limit (unsigned int limit)
 #endif
 }
 
-void 
+void
 _dbus_init_system_log (void)
 {
+#ifdef HAVE_DECL_LOG_PERROR
   openlog ("dbus", LOG_PID | LOG_PERROR, LOG_DAEMON);
+#else
+  openlog ("dbus", LOG_PID, LOG_DAEMON);
+#endif
 }
+
 /**
  * Log a message to the system log file (e.g. syslog on Unix).
  *
@@ -476,6 +481,19 @@ _dbus_system_logv (DBusSystemLogSeverity severity, const char *msg, va_list args
         return;
     }
 
+#ifndef HAVE_DECL_LOG_PERROR
+    {
+      /* vsyslog() won't write to stderr, so we'd better do it */
+      va_list tmp;
+
+      DBUS_VA_COPY (tmp, args);
+      fprintf (stderr, "dbus[" DBUS_PID_FORMAT "]: ", _dbus_getpid ());
+      vfprintf (stderr, msg, tmp);
+      fputc ('\n', stderr);
+      va_end (tmp);
+    }
+#endif
+
   vsyslog (flags, msg, args);
 
   if (severity == DBUS_SYSTEM_LOG_FATAL)