Address rev-parse review feedback

Author: codex

git/repo/fun.py

@@ -190,10 +190,6 @@ def name_to_object(repo: "Repo", name: str, return_ref: bool = False) -> Union[A
         # END handle short shas
     # END find sha if it matches
 
-    if hexsha is None:
-        hexsha = _describe_to_long(repo, name)
-    # END handle describe output
-
     # If we couldn't find an object for what seemed to be a short hexsha, try to find it
     # as reference anyway, it could be named 'aaa' for instance.
     if hexsha is None:
@@ -216,6 +212,10 @@ def name_to_object(repo: "Repo", name: str, return_ref: bool = False) -> Union[A
         # END for each base
     # END handle hexsha
 
+    if hexsha is None:
+        hexsha = _describe_to_long(repo, name)
+    # END handle describe output
+
     # Didn't find any ref, this is an error.
     if return_ref:
         raise BadObject("Couldn't find reference named %r" % name)
@@ -363,6 +363,8 @@ def _tracking_branch_object(repo: "Repo", ref: Optional[SymbolicReference]) -> A
             raise BadName("@{upstream}") from e
     elif isinstance(ref, Head):
         head = ref
+    elif os.fspath(ref.path).startswith("refs/heads/"):
+        head = Head(repo, ref.path)
     else:
         raise BadName("%s@{upstream}" % ref.name)
     # END handle head
@@ -479,7 +481,11 @@ def _find_commit_by_message(
     repo: "Repo", rev: Optional[AnyGitObject], pattern: str, braced: bool = False
 ) -> AnyGitObject:
     pattern, negated = _parse_search(_unescape_braced_regex(pattern) if braced else pattern)
-    regex = re.compile(pattern)
+    try:
+        regex = re.compile(pattern)
+    except re.error as e:
+        raise ValueError("Invalid commit message regex %r" % pattern) from e
+    # END handle invalid regex
     if rev is None:
         commits = repo.iter_commits("--all")
     else:
@@ -527,8 +533,6 @@ def _tree_lookup(obj: AnyGitObject, path: str) -> AnyGitObject:
 
 
 def _peel(obj: AnyGitObject, output_type: str, repo: "Repo", rev: str) -> AnyGitObject:
-    if output_type == "/":
-        return obj
     if output_type.startswith("/"):
         return _find_commit_by_message(repo, obj, output_type[1:], braced=True)
     if output_type == "":

test/test_rev_parse.py

@@ -1,8 +1,14 @@
+# Copyright (C) 2026 Michael Trier (mtrier@gmail.com) and contributors
+#
+# This module is part of GitPython and is released under the
+# 3-Clause BSD License: https://opensource.org/license/bsd-3-clause/
+
 from pathlib import Path
 
 import pytest
 
 from git import Repo
+from git.refs import SymbolicReference
 from gitdb.exc import BadName
 
 
@@ -55,16 +61,21 @@ def rev_parse_repo(tmp_path):
 
 def test_rev_parse_names_hex_and_describe_forms(rev_parse_repo):
     repo = rev_parse_repo["repo"]
+    release = rev_parse_repo["release"]
     merge = rev_parse_repo["merge"]
 
     assert repo.rev_parse("@") == merge
     assert repo.rev_parse("@foo") == merge
     assert repo.rev_parse("aaaaaaaa") == merge
     assert repo.rev_parse(merge.hexsha[:7]) == merge
+    describe_name = "anything-9-g%s" % merge.hexsha[:7]
     assert repo.rev_parse("v1.0-1-g%s" % merge.hexsha[:7]) == merge
-    assert repo.rev_parse("anything-9-g%s" % merge.hexsha[:7]) == merge
+    assert repo.rev_parse(describe_name) == merge
     assert repo.rev_parse("%s-dirty" % merge.hexsha[:7]) == merge
 
+    repo.create_tag(describe_name, ref=release)
+    assert repo.rev_parse(describe_name) == release
+
 
 def test_rev_parse_navigation_and_peeling(rev_parse_repo):
     repo = rev_parse_repo["repo"]
@@ -87,7 +98,8 @@ def test_rev_parse_navigation_and_peeling(rev_parse_repo):
     assert repo.rev_parse("ann^{}") == root
     assert repo.rev_parse("ann^{commit}") == root
     assert repo.rev_parse("HEAD^{tree}") == merge.tree
-    assert repo.rev_parse("HEAD^{/}") == merge
+    with pytest.raises(ValueError):
+        repo.rev_parse("HEAD^{/}")
 
 
 def test_rev_parse_tree_and_index_paths(rev_parse_repo):
@@ -114,6 +126,11 @@ def test_rev_parse_reflog_selectors(rev_parse_repo):
     assert repo.rev_parse("%s@{0}" % main.name) == merge
     assert repo.rev_parse("@{-1}") == side
 
+    repo.create_remote("origin", repo.working_tree_dir)
+    SymbolicReference.create(repo, "refs/remotes/origin/%s" % main.name, merge)
+    main.set_tracking_branch(repo.remotes.origin.refs[main.name])
+    assert repo.rev_parse("%s@{upstream}" % main.name) == merge
+
 
 def test_rev_parse_commit_message_search(rev_parse_repo):
     repo = rev_parse_repo["repo"]
@@ -132,6 +149,10 @@ def test_rev_parse_rejects_invalid_object_specs(rev_parse_repo):
         repo.rev_parse(":")
     with pytest.raises(ValueError):
         repo.rev_parse(":/")
+    with pytest.raises(ValueError):
+        repo.rev_parse(":/[")
+    with pytest.raises(ValueError):
+        repo.rev_parse("HEAD^{/[}")
     with pytest.raises(ValueError):
         repo.rev_parse("@{-0}")
     with pytest.raises(ValueError):