* configure.in: Check for SIGTSTP and SIGCONT signals. Disable

subshell if this test fails.

ChangeLog

@@ -1,3 +1,8 @@
+2002-08-04  Pavel Roskin  <proski@gnu.org>
+
+	* configure.in: Check for SIGTSTP and SIGCONT signals.  Disable
+	subshell if this test fails.
+
 2002-08-03  Pavel Roskin  <proski@gnu.org>
 
 	* syntax/mail.syntax: Colors changed to be more readable.

configure.in

@@ -466,6 +466,19 @@ filel=$ac_cv_filel
 AC_MSG_RESULT([$filel])
 fi 
 
+
+AC_CACHE_CHECK([for SIGTSTP and SIGCONT signals],
+	       [mc_cv_have_sigtstp],
+	       [AC_TRY_LINK(
+[#include <signal.h>
+],
+[kill(1, SIGTSTP);
+kill(1, SIGCONT);
+],
+[mc_cv_have_sigtstp=yes],
+[mc_cv_have_sigtstp=no])])
+
+
 AC_MSG_CHECKING([for subshell support])
 AC_ARG_WITH(subshell,
 	[--with-subshell=optional   To disable concurrent shell by default
@@ -475,26 +488,27 @@ AC_ARG_WITH(subshell,
 	then
 		AC_DEFINE(SUBSHELL_OPTIONAL, 1,
 			  [Define to make subshell support optional])
-		AC_DEFINE(HAVE_SUBSHELL_SUPPORT, 1,
-			  [Define to enable subshell support])
 		result="optional"
 	fi
 	if test x$withval = xyes
         then 
-		AC_DEFINE(HAVE_SUBSHELL_SUPPORT)
 		result="yes"
 	fi],
 	[dnl Default: provide the subshell support on non-ultrix machines
 	case $host_os in
 	ultrix*)
-		result=no
+		result="no"
 		;;
 	*)
-		AC_DEFINE(HAVE_SUBSHELL_SUPPORT)
-		result=yes
+		dnl If SIGTSTP is missing, then no subshell
+		result="$mc_cv_have_sigtstp"
 		;;
 	esac
 ])
+if test "x$result" != xno; then
+	AC_DEFINE(HAVE_SUBSHELL_SUPPORT, 1,
+		  [Define to enable subshell support])
+fi
 AC_MSG_RESULT([$result])
 subshell="$result"