Uniquify automatic wrapper snapshot names

DEVELOPMENT.md

@@ -316,7 +316,7 @@ The wrapper snapshot flow is:
 wrapper_cmd
   -> _extract_paths_from_command()
   -> _common_snapshot_root()
-  -> create auto-YYYYMMDD-HHMMSS state
+   -> create a unique auto-YYYYMMDD-HHMMSS[-N] state
   -> _iter_entries_for_target() for each path
   -> insert each relative path once
   -> run subprocess.run(wrapper_cmd)
@@ -798,7 +798,8 @@ The list of `PlannedChange` objects produced before any mutation occurs.
 The `chguard -- chmod|chown|chgrp ...` mode that saves an automatic pre-command snapshot before running the command.
 
 **Auto snapshot**
-A wrapper-created state named like `auto-YYYYMMDD-HHMMSS`.
+A wrapper-created state named like `auto-YYYYMMDD-HHMMSS`, with a numeric
+suffix when needed to keep same-second snapshots unique.
 
 **Owner restore**
 Restoring numeric uid/gid with `os.chown(..., follow_symlinks=False)`.

README.md

@@ -57,6 +57,8 @@ auto-20251230-161301
 ```
 
 Auto-generated snapshots are visually distinguished in the output so they are easy to identify.
+Snapshots created during the same second use a numeric suffix to remain unique,
+for example `auto-20251230-161301-1`.
 
 ### Scope control
 Restore:

chguard/cli.py

@@ -6,6 +6,7 @@ import grp
 import importlib.metadata
 import os
 import pwd
+import sqlite3
 import stat
 import subprocess
 import sys
@@ -166,6 +167,28 @@ def _common_snapshot_root(paths: list[Path]) -> Path:
     return Path(os.path.commonpath([str(p.resolve()) for p in paths]))
 
 
+def _create_auto_state(
+    conn, root_path: Path, created_by_uid: int
+) -> tuple[int, str]:
+    base_name = f"auto-{datetime.now().strftime('%Y%m%d-%H%M%S')}"
+    suffix = 0
+
+    while True:
+        auto_name = base_name if suffix == 0 else f"{base_name}-{suffix}"
+        try:
+            state_id = create_state(
+                conn,
+                auto_name,
+                str(root_path),
+                created_by_uid,
+                commit=False,
+            )
+        except sqlite3.IntegrityError:
+            suffix += 1
+        else:
+            return state_id, auto_name
+
+
 def _type_for_mode(mode: int) -> str | None:
     if stat.S_ISDIR(mode):
         return "dir"
@@ -451,12 +474,11 @@ def main() -> None:
         paths = _extract_paths_from_command(wrapper_cmd)
 
         if paths:
-            auto_name = f"auto-{datetime.now().strftime('%Y%m%d-%H%M%S')}"
             root_path = _common_snapshot_root(paths)
 
             with conn:
-                state_id = create_state(
+                state_id, auto_name = _create_auto_state(
-                    conn, auto_name, str(root_path), os.getuid(), commit=False
+                    conn, root_path, os.getuid()
                 )
 
                 seen_paths: set[str] = set()

tests/test_cli_restore_preview.py

@@ -2,9 +2,13 @@ from __future__ import annotations
 
 import os
 import sys
+from datetime import datetime
 from pathlib import Path
 from types import SimpleNamespace
 
+import pytest
+
+import chguard.cli as cli
 from chguard.cli import _restore_preview_rows, main
 from chguard.db import connect, create_state, init_db
 from chguard.restore import PlannedChange
@@ -109,3 +113,52 @@ def test_restore_with_only_skipped_items_does_not_prompt(
     output = capsys.readouterr().out
     assert "missing path" in output
     assert "No applicable changes" in output
+
+
+def test_wrapper_uses_unique_auto_names_within_same_second(
+    tmp_path: Path, monkeypatch
+) -> None:
+    db_path = tmp_path / "states.db"
+    target = tmp_path / "target"
+    target.write_text("data", encoding="utf-8")
+
+    class FixedDatetime:
+        @classmethod
+        def now(cls) -> datetime:
+            return datetime(2026, 10, 10, 0, 10, 48)
+
+    monkeypatch.setattr(cli, "datetime", FixedDatetime)
+    monkeypatch.setattr(
+        cli.subprocess,
+        "run",
+        lambda command: SimpleNamespace(returncode=0),
+    )
+
+    for _ in range(2):
+        monkeypatch.setattr(
+            sys,
+            "argv",
+            [
+                "chguard",
+                "--db",
+                str(db_path),
+                "--",
+                "chmod",
+                "600",
+                str(target),
+            ],
+        )
+
+        with pytest.raises(SystemExit) as exc_info:
+            main()
+
+        assert exc_info.value.code == 0
+
+    conn = connect(db_path)
+    rows = conn.execute("SELECT name FROM states ORDER BY id").fetchall()
+    conn.close()
+
+    assert rows == [
+        ("auto-20261010-001048",),
+        ("auto-20261010-001048-1",),
+    ]