pathlib: is_mount() is implemented on Windows on py312+ (#10257)

stdlib/pathlib.pyi

@@ -159,6 +159,10 @@ class Path(PurePath):
         # so it's safer to pretend they don't exist
         def owner(self) -> str: ...
         def group(self) -> str: ...
+
+    # This method does "exist" on Windows on <3.12, but always raises NotImplementedError
+    # On py312+, it works properly on Windows, as with all other platforms
+    if sys.platform != "win32" or sys.version_info >= (3, 12):
         def is_mount(self) -> bool: ...
 
     if sys.version_info >= (3, 9):

tests/stubtest_allowlists/win32-py310.txt

@@ -12,4 +12,5 @@ subprocess.STARTUPINFO.copy
 
 # pathlib methods that exist on Windows, but always raise NotImplementedError,
 # so are omitted from the stub
+pathlib.Path.is_mount
 pathlib.WindowsPath.is_mount

tests/stubtest_allowlists/win32-py311.txt

@@ -15,4 +15,5 @@ subprocess.STARTUPINFO.copy
 
 # pathlib methods that exist on Windows, but always raise NotImplementedError,
 # so are omitted from the stub
+pathlib.Path.is_mount
 pathlib.WindowsPath.is_mount

tests/stubtest_allowlists/win32-py37.txt

@@ -14,6 +14,7 @@ urllib.parse.parse_qsl
 
 # pathlib methods that exist on Windows, but always raise NotImplementedError,
 # so are omitted from the stub
+pathlib.Path.is_mount
 pathlib.WindowsPath.group
 pathlib.WindowsPath.owner
 pathlib.WindowsPath.is_mount

tests/stubtest_allowlists/win32-py38.txt

@@ -15,6 +15,7 @@ subprocess.STARTUPINFO.copy
 
 # pathlib methods that exist on Windows, but always raise NotImplementedError,
 # so are omitted from the stub
+pathlib.Path.is_mount
 pathlib.WindowsPath.group
 pathlib.WindowsPath.owner
 pathlib.WindowsPath.is_mount

tests/stubtest_allowlists/win32-py39.txt

@@ -11,4 +11,5 @@ subprocess.STARTUPINFO.copy
 
 # pathlib methods that exist on Windows, but always raise NotImplementedError,
 # so are omitted from the stub
+pathlib.Path.is_mount
 pathlib.WindowsPath.is_mount

tests/stubtest_allowlists/win32.txt

@@ -66,6 +66,3 @@ tty
 # pathlib functions that rely on modules that don't exist on Windows
 pathlib.Path.owner
 pathlib.Path.group
-# pathlib methods that exist on Windows, but always raise NotImplementedError,
-# so are omitted from the stub
-pathlib.Path.is_mount