GitCommitMessageCheck: match git cat-file replies to tags by order

Signed-off-by: Arthur Zamarin <arthurzam@gentoo.org>

Author: arthurzam

NEWS.rst

@@ -26,6 +26,9 @@ pkgcheck 0.10.47 (unreleased)
 - ``pkgcheck scan``: a bare ``-j`` or ``-j0`` in ``MAKEOPTS`` no longer fails
   the scan (Arthur Zamarin)
 
+- InvalidCommitTag: report ``Fixes`` and ``Reverts`` naming a blob or tree
+  instead of crashing (Arthur Zamarin)
+
 -----------------------------
 pkgcheck 0.10.46 (2026-09-26)
 -----------------------------

src/pkgcheck/checks/git.py

@@ -850,15 +850,15 @@ def _commit_tag(self, tag, values, commit: git.GitCommit):
             return
         self.git_cat_file.stdin.write("\n".join(commits.keys()) + "\n")
         if self.git_cat_file.poll() is None:
-            for _ in range(len(commits)):
+            # replies come in request order, naming found objects by their full hash
+            for value in commits.values():
                 line = self.git_cat_file.stdout.readline().strip()
                 if mo := self._git_cat_file_regex.match(line):
-                    value = mo.group("object")
-                    status = mo.group("status")
-                    if not status.startswith("commit "):
-                        yield InvalidCommitTag(
-                            tag, commits[value], f"{status} commit", commit=commit
-                        )
+                    status = mo.group("status").split()[0]
+                    if status in ("missing", "ambiguous"):
+                        yield InvalidCommitTag(tag, value, f"{status} commit", commit=commit)
+                    elif status != "commit":
+                        yield InvalidCommitTag(tag, value, f"{status}, not a commit", commit=commit)
 
     def feed(self, commit: git.GitCommit):
         if len(commit.message) == 0:

tests/checks/test_git.py

@@ -125,6 +125,16 @@ def test_commit_tags(self):
                     assert isinstance(r, git_mod.InvalidCommitTag)
                     assert f"{status} commit" in r.error
 
+            # existing non-commit object, which git names by its full hash
+            self.check._git_cat_file = None
+            with patch("pkgcheck.checks.git.subprocess.Popen") as git_cat:
+                git_cat.return_value.poll.return_value = None
+                git_cat.return_value.stdout.readline.return_value = f"{ref}0123456789abc blob 3"
+                commit = self.SO_commit(tags=[f"{tag}: {ref}"])
+                r = self.assertReport(self.check, commit)
+                assert isinstance(r, git_mod.InvalidCommitTag)
+                assert "blob, not a commit" in r.error
+
             # valid tag reference
             with patch("pkgcheck.checks.git.subprocess.Popen") as git_cat:
                 self.check._git_cat_file = None