From 0806363b57db10eba8db006899fb76fe8651590c Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Wed, 6 Mar 2024 23:05:51 -0800
Subject: [PATCH] Tell Autoconf to get the version from `ddclient.in`

This avoids the need to maintain the same version string in two
different places.
---
 .autom4te.cfg   |  6 ++++++
 Makefile.am     |  1 +
 configure.ac    | 11 ++++++++++-
 t/version.pl.in |  2 +-
 4 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 .autom4te.cfg

diff --git a/.autom4te.cfg b/.autom4te.cfg
new file mode 100644
index 0000000..2e235ff
--- /dev/null
+++ b/.autom4te.cfg
@@ -0,0 +1,6 @@
+# Disable autom4te cache to ensure that any change to ddclient.in triggers a
+# rebuild of the configure script (which gets the version of ddclient from
+# ddclient.in).  See <https://lists.gnu.org/r/automake/2019-10/msg00002.html>.
+begin-language: "Autoconf-without-aclocal-m4"
+args: --no-cache
+end-language: "Autoconf-without-aclocal-m4"
diff --git a/Makefile.am b/Makefile.am
index a02bdb3..c43b540 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -76,6 +76,7 @@ generated_tests = \
 TESTS = $(handwritten_tests) $(generated_tests)
 $(TESTS): ddclient
 EXTRA_DIST += $(handwritten_tests) \
+	.autom4te.cfg \
 	t/lib/Devel/Autoflush.pm \
 	t/lib/Test/Builder.pm \
 	t/lib/Test/Builder/Formatter.pm \
diff --git a/configure.ac b/configure.ac
index e60c85f..f65b8b3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,5 +1,14 @@
 AC_PREREQ([2.63])
-AC_INIT([ddclient], [3.11.3_0])
+# Get the version from ddclient.in so that the same version string
+# doesn't have to be maintained in two places.  The m4_dquote macro is
+# used instead of quote characters to ensure that the command is only
+# run once.  The command outputs quote characters to prevent
+# incidental expansion (the m4_esyscmd macro does not quote the
+# command output itself, so the command output is subject to
+# expansion).
+AC_INIT([ddclient], m4_dquote(m4_esyscmd([printf '[%s]' "$(./ddclient.in --version=short)"])))
+# Needed because of the above invocation of ddclient.in.
+AC_SUBST([CONFIGURE_DEPENDENCIES], ['$(top_srcdir)/ddclient.in'])
 AC_CONFIG_SRCDIR([ddclient.in])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])
diff --git a/t/version.pl.in b/t/version.pl.in
index 42b1bb0..e7bd863 100644
--- a/t/version.pl.in
+++ b/t/version.pl.in
@@ -4,6 +4,6 @@ use version;
 SKIP: { eval { require Test::Warnings; } or skip($@, 1); }
 eval { require 'ddclient'; } or BAIL_OUT($@);
 
-is(ddclient->VERSION(), version->parse('v@PACKAGE_VERSION@'), "version matches Autoconf config");
+is($ddclient::version, '@PACKAGE_VERSION@', "version matches version in Autoconf");
 
 done_testing();