Guard normal operations-only fast-forward publication

tools/publish_gitea.py

@@ -50,10 +50,18 @@ def check_bundle(args, source):
     resolved = run(["git", "--git-dir", source, "rev-parse", args.tag + "^{}"]).stdout.decode().strip()
     require(resolved == args.commit, "Release tag does not point to reviewed commit")
     refs = remote_refs()
+    if args.ops_update_from:
+        require(args.ops_branch and re.fullmatch(r"[a-f0-9]{40}", args.ops_update_from), "Explicit operations update guard required")
+        require(refs.get("refs/heads/main") == args.commit, "Published release main changed")
+        require(refs.get("refs/tags/" + args.tag + "^{}") == args.commit, "Published signed tag changed")
+        require(refs.get("refs/heads/" + args.ops_branch) == args.ops_update_from, "Operations branch changed")
+        run(["git", "--git-dir", source, "merge-base", "--is-ancestor", args.ops_update_from, "refs/heads/" + args.ops_branch])
+    else:
         require(refs.get("refs/heads/main") == args.old_commit, "Canonical main changed; review before publishing")
         require("refs/tags/" + args.tag not in refs, "Release tag already exists; never overwrite")
     if args.ops_branch:
         require(re.fullmatch(r"ops/[a-z0-9][a-z0-9/-]*", args.ops_branch), "Invalid operations branch")
+        if not args.ops_update_from:
             require("refs/heads/" + args.ops_branch not in refs, "Operations branch already exists; do not overwrite")
         run(["git", "--git-dir", source, "merge-base", "--is-ancestor", args.commit, "refs/heads/" + args.ops_branch])
     return refs
@@ -132,7 +140,8 @@ def publish(args):
         before = check_bundle(args, source)
         state = {"schema": 1, "repository": "gerardo/framebridge", "old_commit": args.old_commit,
                  "commit": args.commit, "tag": args.tag, "bundle_sha256": args.bundle_sha256,
-                 "phase": "CHECKED", "push_performed": False, "token_revoked": False}
+                 "phase": "CHECKED", "push_performed": False, "token_revoked": False,
+                 "ops_update_from": args.ops_update_from}
         if not args.apply:
             print(json.dumps(state, sort_keys=True))
             return
@@ -169,7 +178,7 @@ def publish(args):
             server, stop, thread, client = askpass_server(directory, token)
             env = dict(os.environ, GIT_ASKPASS=str(client), GIT_TERMINAL_PROMPT="0", LC_ALL="C")
             # No force flag. The normal receive-pack checks and Gitea hooks run.
-            refspecs = [args.commit + ":refs/heads/main", "refs/tags/" + args.tag]
+            refspecs = [] if args.ops_update_from else [args.commit + ":refs/heads/main", "refs/tags/" + args.tag]
             if args.ops_branch:
                 refspecs.append("refs/heads/" + args.ops_branch + ":refs/heads/" + args.ops_branch)
             run(["git", "--git-dir", source, "-c", "credential.helper=", "push", "--atomic",
@@ -232,6 +241,7 @@ def main():
     parser.add_argument("--old-commit", required=True)
     parser.add_argument("--tag", required=True)
     parser.add_argument("--ops-branch", help="Publish one new operations branch atomically with the release")
+    parser.add_argument("--ops-update-from", help="Fast-forward only operations from this exact old commit; preserve published main and tag")
     parser.add_argument("--journal", type=Path)
     parser.add_argument("--apply", action="store_true")
     args = parser.parse_args()