scripts: imp code

scripts/make/version.sh

@@ -68,6 +68,15 @@ get_last_minor_zero() {
 		| head -n 1
 }
 
+# get_last_release returns the most recent release tag, regardless whether it's
+# patch, minor, or major one.
+get_last_release() {
+	git tag\
+		| grep -e 'v[0-9]\+\.[0-9]\+\.[0-9]\+$'\
+		| sort -k 1.2,1nr -k 2,2nr -k 3,3nr -t '.'\
+		| head -n 1
+}
+
 channel="${CHANNEL:?please set CHANNEL}"
 readonly channel
 
@@ -132,29 +141,29 @@ in
 	# This pseudo-channel is used to set a proper versions into release
 	# candidate builds.
 
-	# last_beta is the most recent beta version git tag.  Assume the release
-	# candidate branch is always based on the following version's beta branch
-	# and thus the latest beta tag will be described.
-	last_beta="$( git describe --abbrev=0 )"
-	readonly last_beta
+	# last_release is the name of the previous release version's tag.
+	last_release="$( get_last_release )"
 
-	# current_branch is the name of the branch currently checked out.  It's
-	# assumed to be a release candidate branch and have a name like:
-	#
-	#   rc-v1.23.456
-	#
+	# current_branch is the name of the branch currently checked out.
 	current_branch="$( git rev-parse --abbrev-ref HEAD )"
 	readonly current_branch
 
-	# num_commits_since_beta is the number of commits within the branch.
-	num_commits_since_beta="$( git rev-list --count "$last_beta".."$current_branch" )"
-	readonly num_commits_since_beta
+	# The branch should be named like:
+	#
+	#   rc-v12.34.56
+	#
+	if ! echo "$current_branch" | grep -E -e '^rc-v[0-9]+\.[0-9]+\.[0-9]+$' -q
+	then
+		echo "invalid release candidate branch name '$current_branch'" 1>&2
+
+		exit 1
+	fi
 
 	# release_version is the final version of this release candidate.
 	release_version="$( echo "$current_branch" | cut -d '-' -f 2 )"
 	readonly release_version
 
-	version="${release_version}-rc.${num_commits_since_beta}"
+	version="${release_version}-rc.$( git rev-list --count "$last_release"..HEAD )"
 	;;
 (*)
 	echo "invalid channel '$channel', supported values are\