From: Akim Demaille <akim@epita.fr>
Date: Tue, 5 Jun 2001 12:44:13 +0000 (+0000)
Subject: * acgeneral.m4 (_AC_INIT_PARSE_ARGS): `prefix' and `exec_prefix'
X-Git-Tag: AUTOCONF-2.50a~63
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ec1c2ffd436b99f0f61bd190a4a2124cb341d584;p=thirdparty%2Fautoconf.git

* acgeneral.m4 (_AC_INIT_PARSE_ARGS): `prefix' and `exec_prefix'
can be empty.
`*dir' variables cannot be NONE.
Reported by Mark Kettenis.
---

diff --git a/ChangeLog b/ChangeLog
index 8ad75b2a6..24d7f4a9f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2001-06-05  Akim Demaille  <akim@epita.fr>
+
+	* acgeneral.m4 (_AC_INIT_PARSE_ARGS): `prefix' and `exec_prefix'
+	can be empty.
+	`*dir' variables cannot be NONE.
+	Reported by Mark Kettenis.
+
 2001-06-05  Paul Eggert  <eggert@twinsun.com>
 
 	* doc/autoconf.texi: Fix references to Solaris and SunOS versions.
diff --git a/NEWS b/NEWS
index 2caf3680b..f2a4e471c 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,7 @@ Now include stdint.h.
 ** Bug fixes
 - Mostly in the test suite.
 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
+- configure accepts --prefix='' again.
 
 * Major changes in Autoconf 2.50
 
diff --git a/THANKS b/THANKS
index 1e7ba9051..5707edda4 100644
--- a/THANKS
+++ b/THANKS
@@ -91,6 +91,7 @@ Lars J. Aas                 larsa@sim.no
 Marcus Daniels              marcus@sysc.pdx.edu
 Marcus Thiessel             marcus@xemacs.org
 Mark Elbrecht               snowball3@usa.net
+Mark Kettenis               kettenis@gnu.org
 Markku Savela               msa@msa.tte.vtt.fi
 Markus Oberhumer            markus.oberhumer@jk.uni-linz.ac.at
 Martin Buchholz             martin@xemacs.org
diff --git a/acgeneral.m4 b/acgeneral.m4
index 813d3d606..e8ef1be57 100644
--- a/acgeneral.m4
+++ b/acgeneral.m4
@@ -1004,15 +1004,23 @@ if test -n "$ac_prev"; then
   AC_MSG_ERROR([missing argument to $ac_option])
 fi
 
+# Be sure to have absolute paths.
+for ac_var in exec_prefix prefix
+do
+  eval ac_val=$`echo $ac_var`
+  case $ac_val in
+    [[\\/$]]* | ?:[[\\/]]* | NONE | '' ) ;;
+    *)  AC_MSG_ERROR([expected an absolute path for --$ac_var: $ac_val]);;
+  esac
+done
+
 # Be sure to have absolute paths.
 for ac_var in bindir sbindir libexecdir datadir sysconfdir sharedstatedir \
-              localstatedir libdir includedir oldincludedir infodir mandir \
-              exec_prefix prefix
+              localstatedir libdir includedir oldincludedir infodir mandir
 do
   eval ac_val=$`echo $ac_var`
   case $ac_val in
     [[\\/$]]* | ?:[[\\/]]* ) ;;
-    NONE ) ;;
     *)  AC_MSG_ERROR([expected an absolute path for --$ac_var: $ac_val]);;
   esac
 done
diff --git a/configure b/configure
index 51790e42e..164a64b0b 100755
--- a/configure
+++ b/configure
@@ -458,15 +458,24 @@ if test -n "$ac_prev"; then
    { (exit 1); exit 1; }; }
 fi
 
+# Be sure to have absolute paths.
+for ac_var in exec_prefix prefix
+do
+  eval ac_val=$`echo $ac_var`
+  case $ac_val in
+    [\\/$]* | ?:[\\/]* | NONE | '' ) ;;
+    *)  { echo "$as_me: error: expected an absolute path for --$ac_var: $ac_val" >&2
+   { (exit 1); exit 1; }; };;
+  esac
+done
+
 # Be sure to have absolute paths.
 for ac_var in bindir sbindir libexecdir datadir sysconfdir sharedstatedir \
-              localstatedir libdir includedir oldincludedir infodir mandir \
-              exec_prefix prefix
+              localstatedir libdir includedir oldincludedir infodir mandir
 do
   eval ac_val=$`echo $ac_var`
   case $ac_val in
     [\\/$]* | ?:[\\/]* ) ;;
-    NONE ) ;;
     *)  { echo "$as_me: error: expected an absolute path for --$ac_var: $ac_val" >&2
    { (exit 1); exit 1; }; };;
   esac
@@ -787,7 +796,7 @@ if test -z "$CONFIG_SITE"; then
 fi
 for ac_site_file in $CONFIG_SITE; do
   if test -r "$ac_site_file"; then
-    { echo "$as_me:790: loading site script $ac_site_file" >&5
+    { echo "$as_me:799: loading site script $ac_site_file" >&5
 echo "$as_me: loading site script $ac_site_file" >&6;}
     cat "$ac_site_file" >&5
     . "$ac_site_file"
@@ -798,7 +807,7 @@ if test -r "$cache_file"; then
   # Some versions of bash will fail to source /dev/null (special
   # files actually), so we avoid doing that.
   if test -f "$cache_file"; then
-    { echo "$as_me:801: loading cache $cache_file" >&5
+    { echo "$as_me:810: loading cache $cache_file" >&5
 echo "$as_me: loading cache $cache_file" >&6;}
     case $cache_file in
       [\\/]* | ?:[\\/]* ) . $cache_file;;
@@ -806,7 +815,7 @@ echo "$as_me: loading cache $cache_file" >&6;}
     esac
   fi
 else
-  { echo "$as_me:809: creating cache $cache_file" >&5
+  { echo "$as_me:818: creating cache $cache_file" >&5
 echo "$as_me: creating cache $cache_file" >&6;}
   >$cache_file
 fi
@@ -822,30 +831,30 @@ for ac_var in `(set) 2>&1 |
   eval ac_new_val="\$ac_env_${ac_var}_value"
   case $ac_old_set,$ac_new_set in
     set,)
-      { echo "$as_me:825: WARNING: \`$ac_var' was set to \`$ac_old_val' in the previous run" >&5
+      { echo "$as_me:834: WARNING: \`$ac_var' was set to \`$ac_old_val' in the previous run" >&5
 echo "$as_me: WARNING: \`$ac_var' was set to \`$ac_old_val' in the previous run" >&2;}
       ac_suggest_removing_cache=: ;;
     ,set)
-      { echo "$as_me:829: WARNING: \`$ac_var' was not set in the previous run" >&5
+      { echo "$as_me:838: WARNING: \`$ac_var' was not set in the previous run" >&5
 echo "$as_me: WARNING: \`$ac_var' was not set in the previous run" >&2;}
       ac_suggest_removing_cache=: ;;
     ,);;
     *)
       if test "x$ac_old_val" != "x$ac_new_val"; then
-        { echo "$as_me:835: WARNING: \`$ac_var' has changed since the previous run:" >&5
+        { echo "$as_me:844: WARNING: \`$ac_var' has changed since the previous run:" >&5
 echo "$as_me: WARNING: \`$ac_var' has changed since the previous run:" >&2;}
-        { echo "$as_me:837: WARNING:   former value:  $ac_old_val" >&5
+        { echo "$as_me:846: WARNING:   former value:  $ac_old_val" >&5
 echo "$as_me: WARNING:   former value:  $ac_old_val" >&2;}
-        { echo "$as_me:839: WARNING:   current value: $ac_new_val" >&5
+        { echo "$as_me:848: WARNING:   current value: $ac_new_val" >&5
 echo "$as_me: WARNING:   current value: $ac_new_val" >&2;}
         ac_suggest_removing_cache=:
       fi;;
   esac
 done
 if $ac_suggest_removing_cache; then
-  { echo "$as_me:846: WARNING: changes in the environment can compromise the build" >&5
+  { echo "$as_me:855: WARNING: changes in the environment can compromise the build" >&5
 echo "$as_me: WARNING: changes in the environment can compromise the build" >&2;}
-  { echo "$as_me:848: WARNING: consider removing $cache_file and starting over" >&5
+  { echo "$as_me:857: WARNING: consider removing $cache_file and starting over" >&5
 echo "$as_me: WARNING: consider removing $cache_file and starting over" >&2;}
 fi
 
@@ -864,10 +873,10 @@ esac
 echo "#! $SHELL" >conftest.sh
 echo  "exit 0"   >>conftest.sh
 chmod +x conftest.sh
-if { (echo "$as_me:867: PATH=\".;.\"; conftest.sh") >&5
+if { (echo "$as_me:876: PATH=\".;.\"; conftest.sh") >&5
   (PATH=".;."; conftest.sh) 2>&5
   ac_status=$?
-  echo "$as_me:870: \$? = $ac_status" >&5
+  echo "$as_me:879: \$? = $ac_status" >&5
   (exit $ac_status); }; then
   ac_path_separator=';'
 else
@@ -893,7 +902,7 @@ for ac_dir in config $srcdir/config; do
   fi
 done
 if test -z "$ac_aux_dir"; then
-  { { echo "$as_me:896: error: cannot find install-sh or install.sh in config $srcdir/config" >&5
+  { { echo "$as_me:905: error: cannot find install-sh or install.sh in config $srcdir/config" >&5
 echo "$as_me: error: cannot find install-sh or install.sh in config $srcdir/config" >&2;}
    { (exit 1); exit 1; }; }
 fi
@@ -913,7 +922,7 @@ ac_configure="$SHELL $ac_aux_dir/configure" # This should be Cygnus configure.
 # AFS /usr/afsws/bin/install, which mishandles nonexistent args
 # SVR4 /usr/ucb/install, which tries to use the nonexistent group "staff"
 # ./install, which can be erroneously created by make from ./install.sh.
-echo "$as_me:916: checking for a BSD compatible install" >&5
+echo "$as_me:925: checking for a BSD compatible install" >&5
 echo $ECHO_N "checking for a BSD compatible install... $ECHO_C" >&6
 if test -z "$INSTALL"; then
 if test "${ac_cv_path_install+set}" = set; then
@@ -962,7 +971,7 @@ fi
     INSTALL=$ac_install_sh
   fi
 fi
-echo "$as_me:965: result: $INSTALL" >&5
+echo "$as_me:974: result: $INSTALL" >&5
 echo "${ECHO_T}$INSTALL" >&6
 
 # Use test -z because SunOS4 sh mishandles braces in ${var-val}.
@@ -973,7 +982,7 @@ test -z "$INSTALL_SCRIPT" && INSTALL_SCRIPT='${INSTALL}'
 
 test -z "$INSTALL_DATA" && INSTALL_DATA='${INSTALL} -m 644'
 
-echo "$as_me:976: checking whether build environment is sane" >&5
+echo "$as_me:985: checking whether build environment is sane" >&5
 echo $ECHO_N "checking whether build environment is sane... $ECHO_C" >&6
 # Just in case
 sleep 1
@@ -996,7 +1005,7 @@ if (
       # if, for instance, CONFIG_SHELL is bash and it inherits a
       # broken ls alias from the environment.  This has actually
       # happened.  Such a system could not be considered "sane".
-      { { echo "$as_me:999: error: ls -t appears to fail.  Make sure there is not a broken
+      { { echo "$as_me:1008: error: ls -t appears to fail.  Make sure there is not a broken
 alias in your environment" >&5
 echo "$as_me: error: ls -t appears to fail.  Make sure there is not a broken
 alias in your environment" >&2;}
@@ -1009,14 +1018,14 @@ then
    # Ok.
    :
 else
-   { { echo "$as_me:1012: error: newly created file is older than distributed files!
+   { { echo "$as_me:1021: error: newly created file is older than distributed files!
 Check your system clock" >&5
 echo "$as_me: error: newly created file is older than distributed files!
 Check your system clock" >&2;}
    { (exit 1); exit 1; }; }
 fi
 rm -f conftest*
-echo "$as_me:1019: result: yes" >&5
+echo "$as_me:1028: result: yes" >&5
 echo "${ECHO_T}yes" >&6
 if test "$program_transform_name" = s,x,x,; then
   program_transform_name=
@@ -1037,7 +1046,7 @@ test "$program_suffix" != NONE &&
 # sed with no file args requires a program.
 test -z "$program_transform_name" && program_transform_name="s,x,x,"
 
-echo "$as_me:1040: checking whether ${MAKE-make} sets \${MAKE}" >&5
+echo "$as_me:1049: checking whether ${MAKE-make} sets \${MAKE}" >&5
 echo $ECHO_N "checking whether ${MAKE-make} sets \${MAKE}... $ECHO_C" >&6
 set dummy ${MAKE-make}; ac_make=`echo "$2" | sed 'y,./+-,__p_,'`
 if eval "test \"\${ac_cv_prog_make_${ac_make}_set+set}\" = set"; then
@@ -1057,11 +1066,11 @@ fi
 rm -f conftest.make
 fi
 if eval "test \"`echo '$ac_cv_prog_make_'${ac_make}_set`\" = yes"; then
-  echo "$as_me:1060: result: yes" >&5
+  echo "$as_me:1069: result: yes" >&5
 echo "${ECHO_T}yes" >&6
   SET_MAKE=
 else
-  echo "$as_me:1064: result: no" >&5
+  echo "$as_me:1073: result: no" >&5
 echo "${ECHO_T}no" >&6
   SET_MAKE="MAKE=${MAKE-make}"
 fi
@@ -1071,7 +1080,7 @@ PACKAGE=autoconf
 VERSION=2.50a
 
 if test "`cd $srcdir && pwd`" != "`pwd`" && test -f $srcdir/config.status; then
-  { { echo "$as_me:1074: error: source directory already configured; run \"make distclean\" there first" >&5
+  { { echo "$as_me:1083: error: source directory already configured; run \"make distclean\" there first" >&5
 echo "$as_me: error: source directory already configured; run \"make distclean\" there first" >&2;}
    { (exit 1); exit 1; }; }
 fi
@@ -1085,78 +1094,78 @@ cat >>confdefs.h <<EOF
 EOF
 
 missing_dir=`cd $ac_aux_dir && pwd`
-echo "$as_me:1088: checking for working aclocal" >&5
+echo "$as_me:1097: checking for working aclocal" >&5
 echo $ECHO_N "checking for working aclocal... $ECHO_C" >&6
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
 if (aclocal --version) < /dev/null > /dev/null 2>&1; then
    ACLOCAL=aclocal
-   echo "$as_me:1095: result: found" >&5
+   echo "$as_me:1104: result: found" >&5
 echo "${ECHO_T}found" >&6
 else
    ACLOCAL="$SHELL $missing_dir/missing aclocal"
-   echo "$as_me:1099: result: missing" >&5
+   echo "$as_me:1108: result: missing" >&5
 echo "${ECHO_T}missing" >&6
 fi
 
-echo "$as_me:1103: checking for working autoconf" >&5
+echo "$as_me:1112: checking for working autoconf" >&5
 echo $ECHO_N "checking for working autoconf... $ECHO_C" >&6
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
 if (autoconf --version) < /dev/null > /dev/null 2>&1; then
    AUTOCONF=autoconf
-   echo "$as_me:1110: result: found" >&5
+   echo "$as_me:1119: result: found" >&5
 echo "${ECHO_T}found" >&6
 else
    AUTOCONF="$SHELL $missing_dir/missing autoconf"
-   echo "$as_me:1114: result: missing" >&5
+   echo "$as_me:1123: result: missing" >&5
 echo "${ECHO_T}missing" >&6
 fi
 
-echo "$as_me:1118: checking for working automake" >&5
+echo "$as_me:1127: checking for working automake" >&5
 echo $ECHO_N "checking for working automake... $ECHO_C" >&6
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
 if (automake --version) < /dev/null > /dev/null 2>&1; then
    AUTOMAKE=automake
-   echo "$as_me:1125: result: found" >&5
+   echo "$as_me:1134: result: found" >&5
 echo "${ECHO_T}found" >&6
 else
    AUTOMAKE="$SHELL $missing_dir/missing automake"
-   echo "$as_me:1129: result: missing" >&5
+   echo "$as_me:1138: result: missing" >&5
 echo "${ECHO_T}missing" >&6
 fi
 
-echo "$as_me:1133: checking for working autoheader" >&5
+echo "$as_me:1142: checking for working autoheader" >&5
 echo $ECHO_N "checking for working autoheader... $ECHO_C" >&6
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
 if (autoheader --version) < /dev/null > /dev/null 2>&1; then
    AUTOHEADER=autoheader
-   echo "$as_me:1140: result: found" >&5
+   echo "$as_me:1149: result: found" >&5
 echo "${ECHO_T}found" >&6
 else
    AUTOHEADER="$SHELL $missing_dir/missing autoheader"
-   echo "$as_me:1144: result: missing" >&5
+   echo "$as_me:1153: result: missing" >&5
 echo "${ECHO_T}missing" >&6
 fi
 
-echo "$as_me:1148: checking for working makeinfo" >&5
+echo "$as_me:1157: checking for working makeinfo" >&5
 echo $ECHO_N "checking for working makeinfo... $ECHO_C" >&6
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
 if (makeinfo --version) < /dev/null > /dev/null 2>&1; then
    MAKEINFO=makeinfo
-   echo "$as_me:1155: result: found" >&5
+   echo "$as_me:1164: result: found" >&5
 echo "${ECHO_T}found" >&6
 else
    MAKEINFO="$SHELL $missing_dir/missing makeinfo"
-   echo "$as_me:1159: result: missing" >&5
+   echo "$as_me:1168: result: missing" >&5
 echo "${ECHO_T}missing" >&6
 fi
 
@@ -1165,7 +1174,7 @@ AUTOTEST_PATH=..
 
 # Extract the first word of "expr", so it can be a program name with args.
 set dummy expr; ac_word=$2
-echo "$as_me:1168: checking for $ac_word" >&5
+echo "$as_me:1177: checking for $ac_word" >&5
 echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6
 if test "${ac_cv_path_EXPR+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
@@ -1182,7 +1191,7 @@ for ac_dir in $ac_dummy; do
   test -z "$ac_dir" && ac_dir=.
   if $as_executable_p "$ac_dir/$ac_word"; then
    ac_cv_path_EXPR="$ac_dir/$ac_word"
-   echo "$as_me:1185: found $ac_dir/$ac_word" >&5
+   echo "$as_me:1194: found $ac_dir/$ac_word" >&5
    break
 fi
 done
@@ -1193,10 +1202,10 @@ fi
 EXPR=$ac_cv_path_EXPR
 
 if test -n "$EXPR"; then
-  echo "$as_me:1196: result: $EXPR" >&5
+  echo "$as_me:1205: result: $EXPR" >&5
 echo "${ECHO_T}$EXPR" >&6
 else
-  echo "$as_me:1199: result: no" >&5
+  echo "$as_me:1208: result: no" >&5
 echo "${ECHO_T}no" >&6
 fi
 
@@ -1208,7 +1217,7 @@ for ac_prog in gm4 gnum4 m4
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
-echo "$as_me:1211: checking for $ac_word" >&5
+echo "$as_me:1220: checking for $ac_word" >&5
 echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6
 if test "${ac_cv_path_M4+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
@@ -1225,7 +1234,7 @@ for ac_dir in $ac_dummy; do
   test -z "$ac_dir" && ac_dir=.
   if $as_executable_p "$ac_dir/$ac_word"; then
    ac_cv_path_M4="$ac_dir/$ac_word"
-   echo "$as_me:1228: found $ac_dir/$ac_word" >&5
+   echo "$as_me:1237: found $ac_dir/$ac_word" >&5
    break
 fi
 done
@@ -1236,10 +1245,10 @@ fi
 M4=$ac_cv_path_M4
 
 if test -n "$M4"; then
-  echo "$as_me:1239: result: $M4" >&5
+  echo "$as_me:1248: result: $M4" >&5
 echo "${ECHO_T}$M4" >&6
 else
-  echo "$as_me:1242: result: no" >&5
+  echo "$as_me:1251: result: no" >&5
 echo "${ECHO_T}no" >&6
 fi
 
@@ -1247,7 +1256,7 @@ fi
 done
 test -n "$M4" || M4="m4"
 
-echo "$as_me:1250: checking whether m4 supports frozen files" >&5
+echo "$as_me:1259: checking whether m4 supports frozen files" >&5
 echo $ECHO_N "checking whether m4 supports frozen files... $ECHO_C" >&6
 if test "${ac_cv_prog_gnu_m4+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
@@ -1259,10 +1268,10 @@ if test x"$M4" != x; then
   esac
 fi
 fi
-echo "$as_me:1262: result: $ac_cv_prog_gnu_m4" >&5
+echo "$as_me:1271: result: $ac_cv_prog_gnu_m4" >&5
 echo "${ECHO_T}$ac_cv_prog_gnu_m4" >&6
 if test x"$ac_cv_prog_gnu_m4" != xyes; then
-  { { echo "$as_me:1265: error: GNU m4 1.4 is required" >&5
+  { { echo "$as_me:1274: error: GNU m4 1.4 is required" >&5
 echo "$as_me: error: GNU m4 1.4 is required" >&2;}
    { (exit 1); exit 1; }; }
 fi
@@ -1274,7 +1283,7 @@ for ac_prog in mawk gawk nawk awk
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
-echo "$as_me:1277: checking for $ac_word" >&5
+echo "$as_me:1286: checking for $ac_word" >&5
 echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6
 if test "${ac_cv_prog_AWK+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
@@ -1289,7 +1298,7 @@ for ac_dir in $ac_dummy; do
   test -z "$ac_dir" && ac_dir=.
   $as_executable_p "$ac_dir/$ac_word" || continue
 ac_cv_prog_AWK="$ac_prog"
-echo "$as_me:1292: found $ac_dir/$ac_word" >&5
+echo "$as_me:1301: found $ac_dir/$ac_word" >&5
 break
 done
 
@@ -1297,10 +1306,10 @@ fi
 fi
 AWK=$ac_cv_prog_AWK
 if test -n "$AWK"; then
-  echo "$as_me:1300: result: $AWK" >&5
+  echo "$as_me:1309: result: $AWK" >&5
 echo "${ECHO_T}$AWK" >&6
 else
-  echo "$as_me:1303: result: no" >&5
+  echo "$as_me:1312: result: no" >&5
 echo "${ECHO_T}no" >&6
 fi
 
@@ -1308,25 +1317,25 @@ fi
 done
 
 # Generating man pages.
-echo "$as_me:1311: checking for working help2man" >&5
+echo "$as_me:1320: checking for working help2man" >&5
 echo $ECHO_N "checking for working help2man... $ECHO_C" >&6
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
 if (help2man --version) < /dev/null > /dev/null 2>&1; then
    HELP2MAN=help2man
-   echo "$as_me:1318: result: found" >&5
+   echo "$as_me:1327: result: found" >&5
 echo "${ECHO_T}found" >&6
 else
    HELP2MAN="$SHELL $missing_dir/missing help2man"
-   echo "$as_me:1322: result: missing" >&5
+   echo "$as_me:1331: result: missing" >&5
 echo "${ECHO_T}missing" >&6
 fi
 
 # We use a path for perl so the #! line in autoscan will work.
 # Extract the first word of "perl", so it can be a program name with args.
 set dummy perl; ac_word=$2
-echo "$as_me:1329: checking for $ac_word" >&5
+echo "$as_me:1338: checking for $ac_word" >&5
 echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6
 if test "${ac_cv_path_PERL+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
@@ -1343,7 +1352,7 @@ for ac_dir in $ac_dummy; do
   test -z "$ac_dir" && ac_dir=.
   if $as_executable_p "$ac_dir/$ac_word"; then
    ac_cv_path_PERL="$ac_dir/$ac_word"
-   echo "$as_me:1346: found $ac_dir/$ac_word" >&5
+   echo "$as_me:1355: found $ac_dir/$ac_word" >&5
    break
 fi
 done
@@ -1355,17 +1364,17 @@ fi
 PERL=$ac_cv_path_PERL
 
 if test -n "$PERL"; then
-  echo "$as_me:1358: result: $PERL" >&5
+  echo "$as_me:1367: result: $PERL" >&5
 echo "${ECHO_T}$PERL" >&6
 else
-  echo "$as_me:1361: result: no" >&5
+  echo "$as_me:1370: result: no" >&5
 echo "${ECHO_T}no" >&6
 fi
 
 if test "$PERL" != no; then
   PERLSCRIPTS="autoscan autoupdate"
 else
-  { echo "$as_me:1368: WARNING: autoscan and autoupdate will not be built since perl is not found" >&5
+  { echo "$as_me:1377: WARNING: autoscan and autoupdate will not be built since perl is not found" >&5
 echo "$as_me: WARNING: autoscan and autoupdate will not be built since perl is not found" >&2;}
 fi
 
@@ -1381,7 +1390,7 @@ fi
 # AFS /usr/afsws/bin/install, which mishandles nonexistent args
 # SVR4 /usr/ucb/install, which tries to use the nonexistent group "staff"
 # ./install, which can be erroneously created by make from ./install.sh.
-echo "$as_me:1384: checking for a BSD compatible install" >&5
+echo "$as_me:1393: checking for a BSD compatible install" >&5
 echo $ECHO_N "checking for a BSD compatible install... $ECHO_C" >&6
 if test -z "$INSTALL"; then
 if test "${ac_cv_path_install+set}" = set; then
@@ -1430,7 +1439,7 @@ fi
     INSTALL=$ac_install_sh
   fi
 fi
-echo "$as_me:1433: result: $INSTALL" >&5
+echo "$as_me:1442: result: $INSTALL" >&5
 echo "${ECHO_T}$INSTALL" >&6
 
 # Use test -z because SunOS4 sh mishandles braces in ${var-val}.
@@ -1554,7 +1563,7 @@ rm -f confdef2opt.sed
 : ${CONFIG_STATUS=./config.status}
 ac_clean_files_save=$ac_clean_files
 ac_clean_files="$ac_clean_files $CONFIG_STATUS"
-{ echo "$as_me:1557: creating $CONFIG_STATUS" >&5
+{ echo "$as_me:1566: creating $CONFIG_STATUS" >&5
 echo "$as_me: creating $CONFIG_STATUS" >&6;}
 cat >$CONFIG_STATUS <<_ACEOF
 #! $SHELL
@@ -1722,7 +1731,7 @@ cat >>$CONFIG_STATUS <<\EOF
     echo "$ac_cs_version"; exit 0 ;;
   --he | --h)
     # Conflict between --help and --header
-    { { echo "$as_me:1725: error: ambiguous option: $1
+    { { echo "$as_me:1734: error: ambiguous option: $1
 Try \`$0 --help' for more information." >&5
 echo "$as_me: error: ambiguous option: $1
 Try \`$0 --help' for more information." >&2;}
@@ -1750,12 +1759,12 @@ Try \`$0 --help' for more information." >&2;}
   'tests/atconfig' ) CONFIG_FILES="$CONFIG_FILES tests/atconfig" ;;
 
   # This is an error.
-  -*) { { echo "$as_me:1753: error: unrecognized option: $1
+  -*) { { echo "$as_me:1762: error: unrecognized option: $1
 Try \`$0 --help' for more information." >&5
 echo "$as_me: error: unrecognized option: $1
 Try \`$0 --help' for more information." >&2;}
    { (exit 1); exit 1; }; } ;;
-  *) { { echo "$as_me:1758: error: invalid argument: $1" >&5
+  *) { { echo "$as_me:1767: error: invalid argument: $1" >&5
 echo "$as_me: error: invalid argument: $1" >&2;}
    { (exit 1); exit 1; }; };;
   esac
@@ -1980,7 +1989,7 @@ done; }
   esac
 
   if test x"$ac_file" != x-; then
-    { echo "$as_me:1983: creating $ac_file" >&5
+    { echo "$as_me:1992: creating $ac_file" >&5
 echo "$as_me: creating $ac_file" >&6;}
     rm -f "$ac_file"
   fi
@@ -1998,7 +2007,7 @@ echo "$as_me: creating $ac_file" >&6;}
       -) echo $tmp/stdin ;;
       [\\/$]*)
          # Absolute (can't be DOS-style, as IFS=:)
-         test -f "$f" || { { echo "$as_me:2001: error: cannot find input file: $f" >&5
+         test -f "$f" || { { echo "$as_me:2010: error: cannot find input file: $f" >&5
 echo "$as_me: error: cannot find input file: $f" >&2;}
    { (exit 1); exit 1; }; }
          echo $f;;
@@ -2011,7 +2020,7 @@ echo "$as_me: error: cannot find input file: $f" >&2;}
            echo $srcdir/$f
          else
            # /dev/null tree
-           { { echo "$as_me:2014: error: cannot find input file: $f" >&5
+           { { echo "$as_me:2023: error: cannot find input file: $f" >&5
 echo "$as_me: error: cannot find input file: $f" >&2;}
    { (exit 1); exit 1; }; }
          fi;;
diff --git a/lib/autoconf/general.m4 b/lib/autoconf/general.m4
index 813d3d606..e8ef1be57 100644
--- a/lib/autoconf/general.m4
+++ b/lib/autoconf/general.m4
@@ -1004,15 +1004,23 @@ if test -n "$ac_prev"; then
   AC_MSG_ERROR([missing argument to $ac_option])
 fi
 
+# Be sure to have absolute paths.
+for ac_var in exec_prefix prefix
+do
+  eval ac_val=$`echo $ac_var`
+  case $ac_val in
+    [[\\/$]]* | ?:[[\\/]]* | NONE | '' ) ;;
+    *)  AC_MSG_ERROR([expected an absolute path for --$ac_var: $ac_val]);;
+  esac
+done
+
 # Be sure to have absolute paths.
 for ac_var in bindir sbindir libexecdir datadir sysconfdir sharedstatedir \
-              localstatedir libdir includedir oldincludedir infodir mandir \
-              exec_prefix prefix
+              localstatedir libdir includedir oldincludedir infodir mandir
 do
   eval ac_val=$`echo $ac_var`
   case $ac_val in
     [[\\/$]]* | ?:[[\\/]]* ) ;;
-    NONE ) ;;
     *)  AC_MSG_ERROR([expected an absolute path for --$ac_var: $ac_val]);;
   esac
 done