1 files changed, 133 insertions, 0 deletions
diff --git a/debian/changelog.upstream.sh b/debian/changelog.upstream.sh
new file mode 100644
index 0000000..afaec0f
--- /dev/null
+++ b/debian/changelog.upstream.sh
@@ -0,0 +1,133 @@
+#!/bin/sh
+# Generate debian/changelog.upstream from debian/changelog and
+# the git revision log.  Inspired by Gerrit Pape’s
+# debian/changelog.upstream.sh, from the git-core Debian package.
+
+set -e
+
+# If argument matches /^Version: /, output remaining text.
+# Result is true if and only if argument matches.
+version_line() {
+	local line result
+	line=$1
+	result=${line#Version: }
+
+	if test "$result" = "$line"
+	then
+		return 1
+	else
+		printf "%s\n" "$result"
+		return 0
+	fi
+}
+
+# If argument matches /^\* New.*snapshot.*commit /,
+# output remaining text.
+# Result is true if and only if argument matches.
+commit_id_line() {
+	local line result
+	line=$1
+	result=${line#\* New*snapshot*commit }
+
+	if test "$result" = "$line"
+	then
+		return 1
+	else
+		printf "%s\n" "$result"
+		return 0
+	fi
+}
+
+# Read standard input, scanning for a changelog entry of the
+# form “New snapshot, taken from upstream commit <blah>.”
+# Output is <blah>.
+# Fails and writes a message to standard error if no such entry is
+# found before the next Version: line with a different upstream
+# version (or EOF).
+# $1 is the upstream version sought.
+read_commit_id() {
+	local upstream_version line version cid
+	upstream_version=$1
+
+	while read line
+	do
+		if
+			version=$(version_line "$line") &&
+			test "${version%-*}" != "$upstream_version"
+		then
+			break
+		fi
+
+		if cid=$(commit_id_line "$line")
+		then
+			printf "%s\n" "${cid%.}"
+			return 0
+		fi
+	done
+
+	echo >&2 "No commit id for $upstream_version"
+	return 1
+}
+
+last=none
+last_cid=none
+# Add a list of all revisions up to $last to debian/changelog.upstream
+# and set last=$2.
+# $1 is a user-readable name for the commit $2
+add_version() {
+	local new new_cid limiter
+	new=$1
+	new_cid=$2
+
+	if test "$last" = none
+	then
+		: > debian/changelog.upstream
+		last=$new
+		last_cid=$new_cid
+		return 0
+	fi
+
+	exec >> debian/changelog.upstream
+	if test "$new" = none
+	then
+		echo "Version $last:"
+		echo "Version $last:" | tr "[:print:]" -
+		limiter=
+	elif test "$new" = "$last"
+	then
+		return 0
+	else
+		echo "Version $last; changes since $new:"
+		echo "Version $last; changes since $new:" | tr "[:print:]" -
+		limiter="$new_cid.."
+	fi
+	echo
+	git rev-list --no-merges "$limiter$last_cid" |
+	git diff-tree --date=iso --stat --format=medium --stdin
+	test "$new" = none || echo
+
+	last=$new
+	last_cid=$new_cid
+}
+
+dpkg-parsechangelog --format rfc822 --all | {
+while read line
+do
+	if version=$(version_line "$line")
+	then
+		# strip Debian revision
+		upstream_version=${version%-*}
+
+		if git rev-parse --verify -q "v$upstream_version" > /dev/null
+		then
+			# upstream release
+			add_version "$upstream_version" "v$upstream_version"
+		else
+			# snapshot
+			cid=$(read_commit_id "$upstream_version") || exit 1
+			add_version "$upstream_version" "$cid"
+		fi
+	fi
+done
+add_version none none
+}