Upgrade to latest version submitted to Autoconf-patches.

diff --git a/m4/shell.m4 b/m4/shell.m4
index 8ef21e0c2dd3be9983f124318d7d420a92f79212..9c2ce6e5be7b71c06a86eed98601cce2844389b6 100644 (file)
--- a/m4/shell.m4
+++ b/m4/shell.m4
@@ -1,4 +1,4 @@
-#serial 2
+#serial 3
 
 # AC_PROG_SHELL
 # -------------
@@ -28,26 +28,28 @@ AC_DEFUN([AC_PROG_SHELL],
 
       case $ac_cv_path_shell in
       no)
-       ac_dummy=/bin:/usr/bin:/usr/bin/posix:/usr/xpg4/bin:$PATH
-       ac_save_IFS=$IFS; IFS=:
-       for ac_dir in $ac_dummy; do
-         for ac_base in sh bash ksh sh5; do
-           case $ac_dir in
-           /*)
-             rm -f conftest.c
-             if ("$ac_dir/$ac_base" -c "$ac_command") 2>/dev/null; then
-               ac_cv_path_shell="$ac_dir/$ac_base"
-               break
-             fi;;
-           esac
-         done
-         case $ac_cv_path_shell in
-         no) ;;
-         *) break;;
-         esac
-       done
-       rm -f conftest.c
-       IFS=$ac_save_IFS;;
+       # Prefer shells that are more likely to be installed in the
+       # same place on all hosts of this platform.  Therefore, prefer
+       # shells in /bin and /usr/bin to shells in the installer's
+       # PATH.  Also, loop through PATH first and then through
+       # shells, since less-"nice" shells in /bin and /usr/bin are
+       # more likely to be installed than "nicer" shells elsewhere.
+        _AS_PATH_WALK([/bin:/usr/bin:$PATH],
+         [for ac_base in sh bash ksh sh5; do
+            case $as_dir in
+            /*)
+              rm -f conftest.c
+              if ("$as_dir/$ac_base" -c "$ac_command") 2>/dev/null; then
+                ac_cv_path_shell="$as_dir/$ac_base"
+                break
+              fi;;
+            esac
+          done
+          case $ac_cv_path_shell in
+          no) ;;
+          *) break;;
+          esac])
+       rm -f conftest.c;;
       esac])
    AC_MSG_RESULT($ac_cv_path_shell)
    SHELL=$ac_cv_path_shell