Implement needs_push/needs_merge to vcs abstraction

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/tests/test_vcs.py

@@ -85,3 +85,8 @@ class VCSGitTest(RepoTestCase):
         self.assertTrue('authordate' in info)
         self.assertTrue('commit' in info)
         self.assertTrue('commitdate' in info)
+
+    def test_merge(self):
+        repo = GitRepository.clone(self.repo_path, self._tempdir)
+        self.assertFalse(repo.needs_merge('master'))
+        self.assertFalse(repo.needs_push('master'))

weblate/trans/vcs.py

@@ -38,7 +38,6 @@ class Repository(object):
 
     - repository configuration (SubProject.configure_repo)
     - branch configuration (SubProject.configure_branch)
-    - needs merge/push (SubProject.git_needs_merge/push)
     - get object hash (Translation.get_git_blob_hash)
     - commit (Translation.__git_commit)
     - configuration (Translation.__configure_committer)
@@ -143,6 +142,20 @@ class Repository(object):
         """
         raise NotImplementedError()
 
+    def needs_merge(self, branch):
+        """
+        Checks whether repository needs merge with upstream
+        (is missing some revisions).
+        """
+        raise NotImplementedError()
+
+    def needs_push(self, branch):
+        """
+        Checks whether repository needs push to upstream
+        (has additional revisions).
+        """
+        raise NotImplementedError()
+
     def get_revision_info(self, revision):
         """
         Returns dictionary with detailed revision information.
@@ -221,3 +234,25 @@ class GitRepository(Repository):
         result['summary'] = message[0]
 
         return result
+
+    def _log_revisions(self, refspec):
+        """
+        Returns revisin log for given refspec.
+        """
+        return self._execute(
+            ['log', '--oneline', refspec, '--']
+        )
+
+    def needs_merge(self, branch):
+        """
+        Checks whether repository needs merge with upstream
+        (is missing some revisions).
+        """
+        return self._log_revisions('..origin/{0}'.format(branch)) != ''
+
+    def needs_push(self, branch):
+        """
+        Checks whether repository needs push to upstream
+        (has additional revisions).
+        """
+        return self._log_revisions('origin/{0}..'.format(branch)) != ''