Prevent matching bogus parent git directories

flit/vcs/__init__.py

@@ -1,12 +1,24 @@
+import subprocess
 from pathlib import Path
 
 from . import hg
 from . import git
 
+def git_validate_ignore(directory: Path) -> bool:
+    check_ignore = subprocess.run(
+        ['git', 'check-ignore', '.'],
+        cwd=str(directory),
+        stderr=subprocess.DEVNULL,
+        stdout=subprocess.DEVNULL,
+    ).returncode
+    if check_ignore == 0:
+        return False
+    return True
+
 def identify_vcs(directory: Path):
     directory = directory.resolve()
     for p in [directory] + list(directory.parents):
-        if (p / '.git').is_dir():
+        if (p / '.git').is_dir() and git_validate_ignore(directory):
             return git
         if (p / '.hg').is_dir():
             return hg

tests/test_sdist.py

@@ -1,6 +1,7 @@
 import ast
 from os.path import join as pjoin
 from pathlib import Path
+from unittest.mock import patch
 import pytest
 from shutil import which, copy, copytree
 import sys
@@ -81,7 +82,8 @@ def test_get_files_list_git(copy_sample):
 
     builder = sdist.SdistBuilder.from_ini_path(td / 'pyproject.toml')
     with MockCommand('git', LIST_FILES_GIT):
-        files = builder.select_files()
+        with patch('flit.vcs.git_validate_ignore', return_value=True):
+            files = builder.select_files()
 
     assert set(files) == {
         'foo', pjoin('dir1', 'bar'), pjoin('dir1', 'subdir', 'qux'),