From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Debian ZFS on Linux maintainers
 <pkg-zfsonlinux-devel@alioth-lists.debian.net>
Date: Wed, 30 Jan 2019 15:12:04 +0100
Subject: [PATCH] Check-for-META-and-DCH-consistency-in-autoconf

---
 config/zfs-meta.m4 | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/config/zfs-meta.m4 b/config/zfs-meta.m4
index aa0fc1420..f525e2010 100644
--- a/config/zfs-meta.m4
+++ b/config/zfs-meta.m4
@@ -1,9 +1,10 @@
 dnl #
 dnl # DESCRIPTION:
-dnl # Read meta data from the META file.  When building from a git repository
-dnl # the ZFS_META_RELEASE field will be overwritten if there is an annotated
-dnl # tag matching the form ZFS_META_NAME-ZFS_META_VERSION-*.  This allows
-dnl # for working builds to be uniquely identified using the git commit hash.
+dnl # Read meta data from the META file or the debian/changelog file if it
+dnl # exists.  When building from a git repository the ZFS_META_RELEASE field
+dnl # will be overwritten if there is an annotated tag matching the form
+dnl # ZFS_META_NAME-ZFS_META_VERSION-*.  This allows for working builds to be
+dnl # uniquely identified using the git commit hash.
 dnl #
 dnl #    The META file format is as follows:
 dnl #      ^[ ]*KEY:[ \t]+VALUE$
@@ -49,6 +50,7 @@ AC_DEFUN([ZFS_AC_META], [
 	_zfs_ac_meta_type="none"
 	if test -f "$META"; then
 		_zfs_ac_meta_type="META file"
+		_dpkg_parsechangelog=$(dpkg-parsechangelog 2>/dev/null)
 
 		ZFS_META_NAME=_ZFS_AC_META_GETVAL([(Name|Project|Package)]);
 		if test -n "$ZFS_META_NAME"; then
@@ -69,8 +71,30 @@ AC_DEFUN([ZFS_AC_META], [
 			AC_SUBST([ZFS_META_VERSION])
 		fi
 
+		if test -n "${_dpkg_parsechangelog}"; then
+			_dpkg_version=$(echo "${_dpkg_parsechangelog}" \
+				| $AWK '$[]1 == "Version:" { print $[]2; }' \
+				| cut -d- -f1)
+			if test "${_dpkg_version}" != "$ZFS_META_VERSION"; then
+				AC_MSG_ERROR([
+	*** Version $ZFS_META_VERSION in the META file is different than
+	*** version $_dpkg_version in the debian/changelog file. DKMS and DEB
+	*** packaging require that these files have the same version.
+				])
+			fi
+		fi
+
 		ZFS_META_RELEASE=_ZFS_AC_META_GETVAL([Release]);
-		if test ! -f ".nogitrelease" && git rev-parse --git-dir > /dev/null 2>&1; then
+
+		if test -n "${_dpkg_parsechangelog}"; then
+			_dpkg_release=$(echo "${_dpkg_parsechangelog}" \
+				| $AWK '$[]1 == "Version:" { print $[]2; }' \
+				| cut -d- -f2-)
+			if test -n "${_dpkg_release}"; then
+				ZFS_META_RELEASE=${_dpkg_release}
+				_zfs_ac_meta_type="dpkg-parsechangelog"
+			fi
+		elif test ! -f ".nogitrelease" && git rev-parse --git-dir > /dev/null 2>&1; then
 			_match="${ZFS_META_NAME}-${ZFS_META_VERSION}"
 			_alias=$(git describe --match=${_match} 2>/dev/null)
 			_release=$(echo ${_alias}|cut -f3- -d'-'|sed 's/-/_/g')