bpo-37935: Added tests for os.walk(), glob.iglob() and Path.glob() (GH-15956)
Test that they do not keep too many file descriptors open for the host OS in a reasonable test scenario.
See [bpo-37935](https://bugs.python.org/issue37935).
diff --git a/Lib/test/test_glob.py b/Lib/test/test_glob.py
index 767bd37..cba8c7c 100644
--- a/Lib/test/test_glob.py
+++ b/Lib/test/test_glob.py
@@ -264,6 +264,23 @@
expect += [join('sym3', 'EF')]
eq(glob.glob(join('**', 'EF'), recursive=True), expect)
+ def test_glob_many_open_files(self):
+ depth = 30
+ base = os.path.join(self.tempdir, 'deep')
+ p = os.path.join(base, *(['d']*depth))
+ os.makedirs(p)
+ pattern = os.path.join(base, *(['*']*depth))
+ iters = [glob.iglob(pattern, recursive=True) for j in range(100)]
+ for it in iters:
+ self.assertEqual(next(it), p)
+ pattern = os.path.join(base, '**', 'd')
+ iters = [glob.iglob(pattern, recursive=True) for j in range(100)]
+ p = base
+ for i in range(depth):
+ p = os.path.join(p, 'd')
+ for it in iters:
+ self.assertEqual(next(it), p)
+
@skip_unless_symlink
class SymlinkLoopGlobTests(unittest.TestCase):