2003-11-25  Paolo Bonzini  <address@hidden>

	* lib/m4sugar/m4sh.m4 (_AS_BOURNE_COMPATIBLE): New macro,
	extracted from AS_SHELL_SANITIZE.
	(_AS_CHECK_FUNCTIONS_SUPPORT): New macro.
	(AS_SHELL_SANITIZE): Call _AS_BOURNE_COMPATIBLE and
	_AS_CHECK_FUNCTIONS_SUPPORT.
	(_AS_LINENO_PREPARE): Call _AS_CHECK_FUNCTIONS_SUPPORT.

Index: lib/m4sugar/m4sh.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/m4sugar/m4sh.m4,v
retrieving revision 1.107
diff -u -r1.107 m4sh.m4
--- lib/m4sugar/m4sh.m4	24 Nov 2003 10:44:52 -0000	1.107
+++ lib/m4sugar/m4sh.m4	25 Nov 2003 12:46:53 -0000
@@ -147,14 +147,10 @@
 }])])])
 
 
-# AS_SHELL_SANITIZE
-# -----------------
+# _AS_BOURNE_COMPATIBLE
+# ---------------------
 # Try to be as Bourne and/or POSIX as possible.
-m4_defun([AS_SHELL_SANITIZE],
-[## --------------------- ##
-## M4sh Initialization.  ##
-## --------------------- ##
-
+m4_define([_AS_BOURNE_COMPATIBLE], [
 # Be Bourne compatible
 if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then
   emulate sh
@@ -166,7 +162,83 @@
   set -o posix
 fi
 DUALCASE=1; export DUALCASE # for MKS sh
+])
+
+
+# _AS_CHECK_FUNCTIONS_SUPPORT(TESTED-SHELL, MESSAGE)
+# --------------------------------------------------
+# This is a spy to detect "in the wild" shells that do not support
+# shell functions correctly and that do support LINENO but not
+# functions.  It is based on the m4sh.at Autotest testcases.
+m4_define([_AS_CHECK_FUNCTIONS_SUPPORT],
+[$1 <<\EOF
+_AS_BOURNE_COMPATIBLE
+func_return () {
+  (exit [$]1)
+}
+
+func_success () {
+  func_return 0
+}
+
+func_failure () {
+  func_return 1
+}
+
+func_ret_success () {
+  return 0
+}
+
+func_ret_failure () {
+  return 1
+}
+
+if func_success; then
+  if func_failure; then
+    cat <<ENDMSG
+m4_text_wrap([$2 does not have working shell functions (func_failure succeeded).], , , 60)
+
+Please write to address@hidden'
+ENDMSG
+  fi
+else
+  cat <<ENDMSG
+m4_text_wrap([$2 does not have working shell functions (func_success failed).], , , 60)
+
+Please write to address@hidden'
+ENDMSG
+fi
+if func_ret_success; then
+  if func_ret_failure; then
+    cat <<ENDMSG
+m4_text_wrap([$2 does not have working shell functions (func_ret_failure succeeded).], , , 60)
+
+Please write to address@hidden'
+ENDMSG
+  fi
+else
+  cat <<ENDMSG
+m4_text_wrap([$2 does not have working shell functions (func_ret_success failed).], , , 60)
 
+Please write to address@hidden'
+ENDMSG
+fi
+EOF
+])
+
+# AS_SHELL_SANITIZE
+# -----------------
+# Try to be as Bourne and/or POSIX as possible, and find workarounds
+# for the shell's quirks.
+m4_defun([AS_SHELL_SANITIZE],
+[## --------------------- ##
+## M4sh Initialization.  ##
+## --------------------- ##
+
+_AS_BOURNE_COMPATIBLE
+if test -z "$CONFIG_SHELL"; then
+  _AS_CHECK_FUNCTIONS_SUPPORT([$SHELL], [This shell])
+fi
 _AS_UNSET_PREPARE
 
 # Work around bugs in pre-3.0 UWIN ksh.
@@ -539,8 +611,7 @@
   as_lineno_2=$LINENO
   as_lineno_3=`(expr $as_lineno_1 + 1) 2>/dev/null`
   test "x$as_lineno_1" != "x$as_lineno_2" &&
-  test "x$as_lineno_3"  = "x$as_lineno_2" dnl
-])
+  test "x$as_lineno_3"  = "x$as_lineno_2"])
 
 # _AS_LINENO_PREPARE
 # ------------------
@@ -579,6 +650,8 @@
 	     AS_UNSET(BASH_ENV)
 	     AS_UNSET(ENV)
 	     CONFIG_SHELL=$as_dir/$as_base
+	     _AS_CHECK_FUNCTIONS_SUPPORT([$CONFIG_SHELL],
+					 [$CONFIG_SHELL supports LINENO but])
 	     export CONFIG_SHELL
 	     exec "$CONFIG_SHELL" "$[0]" ${1+"address@hidden"}
 	   fi;;
Index: tests/wrapper.in
===================================================================
RCS file: /cvsroot/autoconf/autoconf/tests/wrapper.in,v
retrieving revision 1.5
diff -u -r1.5 wrapper.in
--- tests/wrapper.in	24 Nov 2003 09:09:06 -0000	1.5
+++ tests/wrapper.in	25 Nov 2003 12:46:54 -0000
@@ -3,6 +3,7 @@
 ## M4sh Initialization.  ##
 ## --------------------- ##
 
+
 # Be Bourne compatible
 if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then
   emulate sh
@@ -14,6 +15,78 @@
   set -o posix
 fi
 DUALCASE=1; export DUALCASE # for MKS sh
+
+if test -z "$CONFIG_SHELL"; then
+  $SHELL <<\EOF
+
+# Be Bourne compatible
+if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then
+  emulate sh
+  NULLCMD=:
+  # Zsh 3.x and 4.x performs word splitting on ${1+"$@"}, which
+  # is contrary to our usage.  Disable this feature.
+  alias -g '${1+"$@"}'='"$@"'
+elif test -n "${BASH_VERSION+set}" && (set -o posix) >/dev/null 2>&1; then
+  set -o posix
+fi
+DUALCASE=1; export DUALCASE # for MKS sh
+
+func_return () {
+  (exit $1)
+}
+
+func_success () {
+  func_return 0
+}
+
+func_failure () {
+  func_return 1
+}
+
+func_ret_success () {
+  return 0
+}
+
+func_ret_failure () {
+  return 1
+}
+
+if func_success; then
+  if func_failure; then
+    cat <<ENDMSG
+This shell does not have working shell functions
+(func_failure succeeded).
+
+Please write to address@hidden'
+ENDMSG
+  fi
+else
+  cat <<ENDMSG
+This shell does not have working shell functions
+(func_success failed).
+
+Please write to address@hidden'
+ENDMSG
+fi
+if func_ret_success; then
+  if func_ret_failure; then
+    cat <<ENDMSG
+This shell does not have working shell functions
+(func_ret_failure succeeded).
+
+Please write to address@hidden'
+ENDMSG
+  fi
+else
+  cat <<ENDMSG
+This shell does not have working shell functions
+(func_ret_success failed).
+
+Please write to address@hidden'
+ENDMSG
+fi
+EOF
+fi
 
 # Support unset when possible.
 if ( (MAIL=60; unset MAIL) || exit) >/dev/null 2>&1; then