autoconf: 1999-09-22 Akim Demaille <akim@epita.fr>

From e819cbd112e0fdebf26ecca5a5e6d59202043ac5 Mon Sep 17 00:00:00 2001
From: Akim Demaille <[EMAIL REDACTED]>
Date: Wed, 22 Sep 1999 08:14:03 +0000
Subject: [PATCH] 1999-09-22  Akim Demaille  <akim@epita.fr>

	* acgeneral.m4 (m4_default): New macro.
	(AC_CHECK_LIB): When ACTION-IF-FOUND is specified, don't perform
	the default action.
	Reported by Pavel.
---
 ChangeLog               |  7 +++++++
 acgeneral.m4            | 22 +++++++++++++++++++---
 configure               |  4 ++--
 lib/autoconf/general.m4 | 22 +++++++++++++++++++---
 4 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 3040277a..86d469fe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+1999-09-22  Akim Demaille  <akim@epita.fr>
+
+	* acgeneral.m4 (m4_default): New macro.
+	(AC_CHECK_LIB): When ACTION-IF-FOUND is specified, don't perform
+	the default action.
+	Reported by Pavel.
+
 1999-09-21  Akim Demaille  <akim@epita.fr>
 
 	* acgeneral.m4 (AC_INIT_PARSE_ARGS, --help message): Use quoted
diff --git a/acgeneral.m4 b/acgeneral.m4
index 92dac461..a5aa636d 100644
--- a/acgeneral.m4
+++ b/acgeneral.m4
@@ -79,6 +79,10 @@ dnl If COND is not the empty string, expand IF-TRUE, otherwise IF-FALSE.
 dnl Comparable to ifdef.
 define([ifset], [ifelse([$1],,[$3],[$2])])
 
+dnl m4_default(EXP1, EXP2)
+dnl ----------------------
+dnl Returns EXP1 if non empty, otherwisee EXP2.
+define([m4_default], [ifset([$1], [$1], [$2])])
 
 dnl ### Defining macros
 
@@ -1070,6 +1074,8 @@ AC_DEFUN(AC_INIT_BINSH,
 ])
 
 dnl AC_INIT(UNIQUE-FILE-IN-SOURCE-DIR)
+dnl ----------------------------------
+dnl Output the preamble of the `configure' script.
 AC_DEFUN(AC_INIT,
 [sinclude(acsite.m4)dnl
 sinclude(./aclocal.m4)dnl
@@ -1089,6 +1095,15 @@ AC_DEFUN(AC_INCLUDE,
 ])])
 
 dnl AC_INIT_PREPARE(UNIQUE-FILE-IN-SOURCE-DIR)
+dnl ------------------------------------------
+dnl Called by AC_INIT to buid the preamble of the `configure' scripts.
+dnl 1. Trap and clean up various tmp files.
+dnl 2. Set up the fd and output files
+dnl 3. Remember the options given to `configure' for `config.status --recheck'.
+dnl 4. Ensure a correct environment
+dnl 5. Find `$srcdir', and check its validity by verifying the presence of
+dnl    UNIQUE-FILE-IN-SOURCE-DIR.
+dnl 6. Required macros (cache, default AC_SUBST etc.)
 AC_DEFUN(AC_INIT_PREPARE,
 [trap 'rm -fr conftest* confdefs* core core.* *.core $ac_clean_files; exit 1' 1 2 15
 
@@ -2140,10 +2155,11 @@ char $2();
 AC_VAR_SET(ac_var, yes), AC_VAR_SET(ac_var, no))
 LIBS="$ac_save_LIBS"])
 AC_SHELL_IFELSE(test AC_VAR_GET(ac_var) = yes,
-               [AC_DEFINE_UNQUOTED(AC_TR_CPP(HAVE_LIB$1))
+                m4_default([$3],
+                          [AC_DEFINE_UNQUOTED(AC_TR_CPP(HAVE_LIB$1))
   LIBS="-l$1 $LIBS"
-  $3],
-               [$4])dnl
+]),
+                [$4])dnl
 AC_VAR_POPDEF([ac_var])dnl
 ])dnl AC_CHECK_LIB
 
diff --git a/configure b/configure
index 2003623f..9618d0e3 100755
--- a/configure
+++ b/configure
@@ -151,8 +151,8 @@ do
     # Omit some internal or obsolete options to make the list less imposing.
     # This message is too long to be a string in the A/UX 3.1 sh.
     cat << \EOF
-`configure' configures software source code packages to adapt to many
-kinds of systems.
+`configure' configures software source code packages to adapt to many kinds
+of systems.
 
 Usage: configure [OPTION]... [VAR=VALUE]... [HOST]
 
diff --git a/lib/autoconf/general.m4 b/lib/autoconf/general.m4
index 92dac461..a5aa636d 100644
--- a/lib/autoconf/general.m4
+++ b/lib/autoconf/general.m4
@@ -79,6 +79,10 @@ dnl If COND is not the empty string, expand IF-TRUE, otherwise IF-FALSE.
 dnl Comparable to ifdef.
 define([ifset], [ifelse([$1],,[$3],[$2])])
 
+dnl m4_default(EXP1, EXP2)
+dnl ----------------------
+dnl Returns EXP1 if non empty, otherwisee EXP2.
+define([m4_default], [ifset([$1], [$1], [$2])])
 
 dnl ### Defining macros
 
@@ -1070,6 +1074,8 @@ AC_DEFUN(AC_INIT_BINSH,
 ])
 
 dnl AC_INIT(UNIQUE-FILE-IN-SOURCE-DIR)
+dnl ----------------------------------
+dnl Output the preamble of the `configure' script.
 AC_DEFUN(AC_INIT,
 [sinclude(acsite.m4)dnl
 sinclude(./aclocal.m4)dnl
@@ -1089,6 +1095,15 @@ AC_DEFUN(AC_INCLUDE,
 ])])
 
 dnl AC_INIT_PREPARE(UNIQUE-FILE-IN-SOURCE-DIR)
+dnl ------------------------------------------
+dnl Called by AC_INIT to buid the preamble of the `configure' scripts.
+dnl 1. Trap and clean up various tmp files.
+dnl 2. Set up the fd and output files
+dnl 3. Remember the options given to `configure' for `config.status --recheck'.
+dnl 4. Ensure a correct environment
+dnl 5. Find `$srcdir', and check its validity by verifying the presence of
+dnl    UNIQUE-FILE-IN-SOURCE-DIR.
+dnl 6. Required macros (cache, default AC_SUBST etc.)
 AC_DEFUN(AC_INIT_PREPARE,
 [trap 'rm -fr conftest* confdefs* core core.* *.core $ac_clean_files; exit 1' 1 2 15
 
@@ -2140,10 +2155,11 @@ char $2();
 AC_VAR_SET(ac_var, yes), AC_VAR_SET(ac_var, no))
 LIBS="$ac_save_LIBS"])
 AC_SHELL_IFELSE(test AC_VAR_GET(ac_var) = yes,
-               [AC_DEFINE_UNQUOTED(AC_TR_CPP(HAVE_LIB$1))
+                m4_default([$3],
+                          [AC_DEFINE_UNQUOTED(AC_TR_CPP(HAVE_LIB$1))
   LIBS="-l$1 $LIBS"
-  $3],
-               [$4])dnl
+]),
+                [$4])dnl
 AC_VAR_POPDEF([ac_var])dnl
 ])dnl AC_CHECK_LIB