filter-repo: handle origin refs without origin remote

git-svn creates references of the form refs/remotes/origin/..., even
though it does not actually set up an origin remote.  Prior to
  a12d742 (filter-repo: notify users when we remove the origin
                remote, 2024-07-30)
this would have resulted in a
  fatal: No such remote: 'origin'
error from the attempt to run `git remote rm origin`.  However, the exit
status of the command was ignored so filter-repo would have continued on
and ended up getting the right result, just scaring users.  Still
suboptimal, but at least it worked.  Since the above-mentioned commit,
though, the code would die with a traceback stating that
b'remote.origin.url' was not found in self._config_settings.

Just return early from _migrate_origin_to_heads() when there is no
remote configured to avoid these problems.

Signed-off-by: Elijah Newren <[email protected]>

git-filter-repo

@@ -3863,6 +3863,8 @@ class RepoFilter(object):
       raise SystemExit(_("git update-ref failed; see above")) # pragma: no cover
 
     # Now remove the origin remote
+    if b'remote.origin.url' not in self._config_settings:
+      return
     url = self._config_settings[b'remote.origin.url'].decode(errors='replace')
     m = _("NOTICE: Removing 'origin' remote; see 'Why is my origin removed?'\n"
           "        in the manual if you want to push back there.\n"

t/t9390-filter-repo.sh

@@ -1977,4 +1977,20 @@ test_expect_success 'failure to run cleanup' '
 	)
 '
 
+test_expect_success 'origin refs without origin remote does not die' '
+	test_create_repo origin_refs_with_origin_remote &&
+	(
+		cd origin_refs_with_origin_remote &&
+
+		test_commit numbers &&
+		git update-ref refs/remotes/origin/svnhead master &&
+
+		git filter-repo --force --path-rename numbers.t:values.t &&
+
+		git show svnhead:values.t >actual &&
+		echo numbers >expect &&
+		test_cmp expect actual
+	)
+'
+
 test_done