util: Resolve ref if duplicate branches are present

If the repo contains the same name under multiple directories, make the
resolving work by filtering only to refs/heads and refs/tags.

Fixes: https://pagure.io/pungi/issue/1180
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

pungi/util.py

@@ -263,7 +263,10 @@ def resolve_git_ref(repourl, ref):
 
     _, output = git_ls_remote(repourl, ref)
 
-    lines = [line for line in output.split('\n') if line]
+    lines = []
+    for line in output.split("\n"):
+        if line and ("refs/heads/" in line or "refs/tags/" in line or "HEAD" in line):
+            lines.append(line)
     if len(lines) == 0:
         # Branch does not exist in remote repo
         raise GitUrlResolveError(
@@ -272,7 +275,7 @@ def resolve_git_ref(repourl, ref):
     if len(lines) != 1:
         # This should never happen. HEAD can not match multiple commits in a
         # single repo, and there can not be a repo without a HEAD.
-        raise GitUrlResolveError("Failed to resolve %s", repourl)
+        raise GitUrlResolveError("Failed to resolve %r in %s" % (ref, repourl))
 
     return lines[0].split()[0]
 

tests/test_util.py

@@ -47,6 +47,20 @@ class TestGitRefResolver(unittest.TestCase):
         ref = util.resolve_git_ref("https://git.example.com/repo.git", "a" * 40)
         self.assertEqual(ref, "a" * 40)
 
+    @mock.patch('pungi.util.run')
+    def test_resolve_ref_multiple_matches(self, run):
+        run.return_value = (
+            0, "CAFEBABE\trefs/heads/master\nBABECAFE\trefs/remotes/origin/master"
+        )
+
+        ref = util.resolve_git_ref("https://git.example.com/repo.git", "master")
+
+        self.assertEqual(ref, "CAFEBABE")
+        run.assert_called_once_with(
+            ["git", "ls-remote", "https://git.example.com/repo.git", "master"],
+            universal_newlines=True,
+        )
+
     @mock.patch('pungi.util.run')
     def test_resolve_missing_spec(self, run):
         url = util.resolve_git_url('https://git.example.com/repo.git')