From aaf49a5c22f8de5544bffe6a960a544fca942378 Mon Sep 17 00:00:00 2001
From: Alan Hamlett <alan.hamlett@gmail.com>
Date: Wed, 1 Jun 2016 10:08:00 +0200
Subject: [PATCH] prevent tracking git branch with detached head

---
 .../git-with-detached-head/dot_git/HEAD       |  1 +
 .../git-with-detached-head/dot_git/config     |  7 +++++++
 .../git-with-detached-head/emptyfile.txt      |  0
 tests/test_project.py                         | 20 +++++++++++++++++++
 wakatime/projects/git.py                      |  9 +++++++--
 5 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 tests/samples/projects/git-with-detached-head/dot_git/HEAD
 create mode 100644 tests/samples/projects/git-with-detached-head/dot_git/config
 create mode 100644 tests/samples/projects/git-with-detached-head/emptyfile.txt

diff --git a/tests/samples/projects/git-with-detached-head/dot_git/HEAD b/tests/samples/projects/git-with-detached-head/dot_git/HEAD
new file mode 100644
index 0000000..e00132a
--- /dev/null
+++ b/tests/samples/projects/git-with-detached-head/dot_git/HEAD
@@ -0,0 +1 @@
+f4f242d698fa07c298592a66d6546ac9b6b34d1e
diff --git a/tests/samples/projects/git-with-detached-head/dot_git/config b/tests/samples/projects/git-with-detached-head/dot_git/config
new file mode 100644
index 0000000..6c9406b
--- /dev/null
+++ b/tests/samples/projects/git-with-detached-head/dot_git/config
@@ -0,0 +1,7 @@
+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = false
+	logallrefupdates = true
+	ignorecase = true
+	precomposeunicode = true
diff --git a/tests/samples/projects/git-with-detached-head/emptyfile.txt b/tests/samples/projects/git-with-detached-head/emptyfile.txt
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_project.py b/tests/test_project.py
index c4bdbe2..81b9bd1 100644
--- a/tests/test_project.py
+++ b/tests/test_project.py
@@ -166,6 +166,26 @@ class LanguagesTestCase(utils.TestCase):
         self.assertEquals('git', self.patched['wakatime.offlinequeue.Queue.push'].call_args[0][0]['project'])
         self.assertEquals('master', self.patched['wakatime.offlinequeue.Queue.push'].call_args[0][0].get('branch'))
 
+    def test_git_detached_head_not_used_as_branch(self):
+        response = Response()
+        response.status_code = 0
+        self.patched['wakatime.packages.requests.adapters.HTTPAdapter.send'].return_value = response
+
+        tempdir = tempfile.mkdtemp()
+        shutil.copytree('tests/samples/projects/git-with-detached-head', os.path.join(tempdir, 'git'))
+        shutil.move(os.path.join(tempdir, 'git', 'dot_git'), os.path.join(tempdir, 'git', '.git'))
+
+        now = u(int(time.time()))
+        entity = os.path.join(tempdir, 'git', 'emptyfile.txt')
+        config = 'tests/samples/configs/good_config.cfg'
+
+        args = ['--file', entity, '--config', config, '--time', now]
+
+        execute(args)
+
+        self.assertEquals('git', self.patched['wakatime.offlinequeue.Queue.push'].call_args[0][0]['project'])
+        self.assertNotIn('branch', self.patched['wakatime.offlinequeue.Queue.push'].call_args[0][0])
+
     def test_svn_project_detected(self):
         response = Response()
         response.status_code = 0
diff --git a/wakatime/projects/git.py b/wakatime/projects/git.py
index 7f98a4d..e42b702 100644
--- a/wakatime/projects/git.py
+++ b/wakatime/projects/git.py
@@ -38,11 +38,11 @@ class Git(BaseProject):
             head = os.path.join(self._project_base(), '.git', 'HEAD')
             try:
                 with open(head, 'r', encoding='utf-8') as fh:
-                    return u(fh.readline().strip().rsplit('/', 1)[-1])
+                    return self._get_branch_from_head_file(fh.readline())
             except UnicodeDecodeError:  # pragma: nocover
                 try:
                     with open(head, 'r', encoding=sys.getfilesystemencoding()) as fh:
-                        return u(fh.readline().strip().rsplit('/', 1)[-1])
+                        return self._get_branch_from_head_file(fh.readline())
                 except:
                     log.traceback('warn')
             except IOError:  # pragma: nocover
@@ -64,3 +64,8 @@ class Git(BaseProject):
         if split_path[1] == '':
             return None
         return self._find_git_config_file(split_path[0])
+
+    def _get_branch_from_head_file(self, line):
+        if u(line.strip()).startswith('ref: '):
+            return u(line.strip().rsplit('/', 1)[-1])
+        return None