Issue #23076: Path.glob() now raises a ValueError if it's called with an

invalid pattern.

Patch by Thomas Nyberg.

Lib/pathlib.py

@@ -1065,6 +1065,8 @@ class Path(PurePath):
         """Iterate over this subtree and yield all existing files (of any
         kind, including directories) matching the given pattern.
         """
+        if not pattern:
+            raise ValueError("Unacceptable pattern: {!r}".format(pattern))
         pattern = self._flavour.casefold(pattern)
         drv, root, pattern_parts = self._flavour.parse_parts((pattern,))
         if drv or root:

Lib/test/test_pathlib.py

@@ -1969,6 +1969,11 @@ class PathTest(_BasePathTest, unittest.TestCase):
         else:
             self.assertRaises(NotImplementedError, pathlib.WindowsPath)
 
+    def test_glob_empty_pattern(self):
+        p = self.cls()
+        with self.assertRaisesRegex(ValueError, 'Unacceptable pattern'):
+            list(p.glob(''))
+
 
 @only_posix
 class PosixPathTest(_BasePathTest, unittest.TestCase):

Misc/ACKS

@@ -1042,6 +1042,7 @@ Neal Norwitz
 Mikhail Novikov
 Michal Nowikowski
 Steffen Daode Nurpmeso
+Thomas Nyberg
 Nigel O'Brian
 John O'Connor
 Kevin O'Connor

Misc/NEWS

@@ -166,6 +166,9 @@ Library
 - Issue #26202: copy.deepcopy() now correctly copies range() objects with
   non-atomic attributes.
 
+- Issue #23076: Path.glob() now raises a ValueError if it's called with an
+  invalid pattern.  Patch by Thomas Nyberg.
+
 - Issue #19883: Fixed possible integer overflows in zipimport.
 
 - Issue #26227: On Windows, getnameinfo(), gethostbyaddr() and