Support git unicode branches

Use `gitpython` to get repository branches instead of our custom/hacky
csv parser.

With this change, we loose the output from `git branch -r` command
shown to the user under the build output.

readthedocs/rtd_tests/tests/test_backend.py

@@ -49,30 +49,34 @@ def setUp(self):
         self.dummy_conf.submodules.include = ALL
         self.dummy_conf.submodules.exclude = []
 
-    def test_parse_branches(self):
-        data = """
-        develop
-        master
-        release/2.0.0
-        origin/2.0.X
-        origin/HEAD -> origin/master
-        origin/master
-        origin/release/2.0.0
-        origin/release/foo/bar
-        """
-
-        expected_ids = [
-            ('develop', 'develop'),
-            ('master', 'master'),
-            ('release/2.0.0', 'release/2.0.0'),
-            ('origin/2.0.X', '2.0.X'),
-            ('origin/master', 'master'),
-            ('origin/release/2.0.0', 'release/2.0.0'),
-            ('origin/release/foo/bar', 'release/foo/bar'),
+    def test_git_branches(self):
+        repo_path = self.project.repo
+        default_branches = [
+            # comes from ``make_test_git`` function
+            'submodule',
+            'relativesubmodule',
+            'invalidsubmodule',
         ]
-        given_ids = [(x.identifier, x.verbose_name) for x in
-                     self.project.vcs_repo().parse_branches(data)]
-        self.assertEqual(expected_ids, given_ids)
+        branches = [
+            'develop',
+            'master',
+            '2.0.X',
+            'release/2.0.0',
+            'release/foo/bar',
+            'release-ünîø∂é',
+        ]
+        for branch in branches:
+            create_git_branch(repo_path, branch)
+
+        repo = self.project.vcs_repo()
+        # We aren't cloning the repo,
+        # so we need to hack the repo path
+        repo.working_dir = repo_path
+
+        self.assertEqual(
+            set(branches + default_branches),
+            {branch.verbose_name for branch in repo.branches},
+        )
 
     def test_git_checkout(self):
         repo = self.project.vcs_repo()
@@ -90,7 +94,7 @@ def test_git_tags(self):
         repo.working_dir = repo_path
         self.assertEqual(
             set(['v01', 'v02', 'release-ünîø∂é']),
-            set(vcs.verbose_name for vcs in repo.tags)
+            {vcs.verbose_name for vcs in repo.tags},
         )
 
     def test_check_for_submodules(self):

readthedocs/vcs_support/backends/git.py

@@ -174,51 +174,14 @@ def tags(self):
 
     @property
     def branches(self):
-        # Only show remote branches
-        retcode, stdout, _ = self.run(
-            'git',
-            'branch',
-            '-r',
-            record_as_success=True,
-        )
-        # error (or no branches found)
-        if retcode != 0:
-            return []
-        return self.parse_branches(stdout)
-
-    def parse_branches(self, data):
-        """
-        Parse output of git branch -r.
-
-        e.g.:
-
-              origin/2.0.X
-              origin/HEAD -> origin/master
-              origin/develop
-              origin/master
-              origin/release/2.0.0
-              origin/release/2.1.0
-        """
-        clean_branches = []
-        # StringIO below is expecting Unicode data, so ensure that it gets it.
-        if not isinstance(data, str):
-            data = str(data)
-        delimiter = str(' ').encode('utf-8') if PY2 else str(' ')
-        raw_branches = csv.reader(StringIO(data), delimiter=delimiter)
-        for branch in raw_branches:
-            branch = [f for f in branch if f not in ('', '*')]
-            # Handle empty branches
-            if branch:
-                branch = branch[0]
-                if branch.startswith('origin/'):
-                    verbose_name = branch.replace('origin/', '')
-                    if verbose_name in ['HEAD']:
-                        continue
-                    clean_branches.append(
-                        VCSVersion(self, branch, verbose_name))
-                else:
-                    clean_branches.append(VCSVersion(self, branch, branch))
-        return clean_branches
+        repo = git.Repo(self.working_dir)
+        versions = []
+        for branch in repo.branches:
+            verbose_name = branch.name
+            if verbose_name.startswith('origin/'):
+                verbose_name = verbose_name.replace('origin/', '')
+            versions.append(VCSVersion(self, str(branch), verbose_name))
+        return versions
 
     @property
     def commit(self):