From 95b09bda4f36a974b85d5c6a45e8b9af51df8584 Mon Sep 17 00:00:00 2001
From: Richard Boulton <richard@tartarus.org>
Date: Fri, 3 Aug 2001 11:57:13 +0000
Subject: [PATCH] 2001-08-03  Richard Boulton <richard@tartarus.org>

	* automake.in (value_to_list): Check for whether $from is defined,
	rather than whether it is true, so that empty $froms are allowed in
	substitution reference patterns.

	* tests/substref.test: New file: test behavior of substitution
	references when the $from side of the substitution is empty.
	* tests/Makefile.am (TESTS): Added substref.test.
---
 ChangeLog           | 10 ++++++++++
 automake.in         |  2 +-
 tests/Makefile.am   |  1 +
 tests/Makefile.in   |  1 +
 tests/substref.test | 46 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100755 tests/substref.test

diff --git a/ChangeLog b/ChangeLog
index 0243b59d..ec401316 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2001-08-03  Richard Boulton <richard@tartarus.org>
+
+	* automake.in (value_to_list): Check for whether $from is defined,
+	rather than whether it is true, so that empty $froms are allowed in
+	substitution reference patterns.
+
+	* tests/substref.test: New file: test behavior of substitution
+	references when the $from side of the substitution is empty.
+	* tests/Makefile.am (TESTS): Added substref.test.
+
 2001-08-03  Alexandre Duret-Lutz  <duret_g@epita.fr>
 
 	* m4/install-sh.m4: New file.
diff --git a/automake.in b/automake.in
index 125829bb..cecb270f 100755
--- a/automake.in
+++ b/automake.in
@@ -6113,7 +6113,7 @@ sub value_to_list
 	    @temp_list = &variable_value_as_list_worker ($1, $cond, $var);
 
 	    # Now rewrite the value if appropriate.
-	    if ($from)
+	    if (defined $from)
 	    {
 		grep (s/$from$/$to/, @temp_list);
 	    }
diff --git a/tests/Makefile.am b/tests/Makefile.am
index fc9bfda9..7932b2ce 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -275,6 +275,7 @@ subobj6.test \
 subobj7.test \
 subobj8.test \
 subst.test \
+substref.test \
 substtarg.test \
 suffix.test \
 suffix2.test \
diff --git a/tests/Makefile.in b/tests/Makefile.in
index d600297d..542e78e8 100644
--- a/tests/Makefile.in
+++ b/tests/Makefile.in
@@ -343,6 +343,7 @@ subobj6.test \
 subobj7.test \
 subobj8.test \
 subst.test \
+substref.test \
 substtarg.test \
 suffix.test \
 suffix2.test \
diff --git a/tests/substref.test b/tests/substref.test
new file mode 100755
index 00000000..750a4040
--- /dev/null
+++ b/tests/substref.test
@@ -0,0 +1,46 @@
+#! /bin/sh
+
+# Test for bug in variable substitution references when left hand pattern is
+# null.
+# Report from Richard Boulton
+
+. $srcdir/defs || exit 1
+
+cat > configure.in << 'END'
+AC_INIT(hello.c)
+AM_INIT_AUTOMAKE(hello,0.23)
+AC_PROG_CC
+AC_OUTPUT(Makefile)
+END
+
+cat > hello.c << 'END'
+END
+
+cat > Makefile.am << 'END'
+
+var1 = dlmain
+
+var2 = $(var1:=.)
+
+helldl_SOURCES = $(var2:=c)
+
+echorule:
+	@echo $(helldl_SOURCES) $(helldl_OBJECTS)
+
+bin_PROGRAMS = helldl
+END
+
+$needs_autoconf
+(gcc -v) > /dev/null 2>&1 || exit 77
+
+set -e
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE -a
+
+CC='gcc' ./configure
+
+val=`$MAKE echorule`;
+echo $val
+test "x$val" = "xdlmain.c dlmain.o"
-- 
2.43.5