From 8418fae82b0c68e58c686c9d1f3e2e92d6629f68 Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@nym.se>
Date: Thu, 10 Mar 2016 10:24:11 +0100
Subject: [PATCH] Add branch name to build version when appropriate

---
 build.go | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/build.go b/build.go
index 797acf1ce..c0fd19966 100644
--- a/build.go
+++ b/build.go
@@ -492,12 +492,41 @@ func getVersion() string {
 	}
 	// ... then see if we have a Git tag.
 	if ver, err := getGitVersion(); err == nil {
+		if strings.Contains(ver, "-") {
+			// The version already contains a hash and stuff. See if we can
+			// find a current branch name to tack onto it as well.
+			return ver + getBranchSuffix()
+		}
 		return ver
 	}
 	// This seems to be a dev build.
 	return "unknown-dev"
 }
 
+func getBranchSuffix() string {
+	bs, err := runError("git", "branch", "-a", "--contains")
+	if err != nil {
+		return ""
+	}
+
+	branches := bytes.Split(bs, []byte{'\n'})
+	if len(branches) == 0 {
+		return ""
+	}
+
+	// "git branch" returns the current branch with an asterisk and space in
+	// "front of it, otherwise just spaces. Remove all that stuff.
+	branch := bytes.TrimLeft(branches[0], " \t*")
+
+	// The branch name may be on the form "remotes/origin/foo" from which we
+	// just want "foo".
+	parts := bytes.Split(branch, []byte{'/'})
+	if len(parts) == 0 || len(parts[len(parts)-1]) == 0 {
+		return ""
+	}
+	return "-" + string(parts[len(parts)-1])
+}
+
 func buildStamp() int64 {
 	bs, err := runError("git", "show", "-s", "--format=%ct")
 	if err != nil {