Hello. While working on issue8579, I noticed that there is no way to detach a key from the registry, loaded with LoadKey function. The attached patch exposes RegUnLoadKeyW as winreg.UnloadKey. Also, this patch adds a new script in the test folder, windows_helper.py, which could be an useful addition for testing Windows specific issues, like acquiring / releasing a privilege.

It needs administrator elevation for running the test. I'll update the patch to skip the test if the user doesn't have elevation.

This version of the patch skips the test if the privileges can't be acquired.

ctypes LibraryLoader instances cache CDLL/WinDLL instances, which cache function pointers. Using the global ctypes.cdll and ctypes.windll loaders can lead to conflicting definitions for restype, argtypes, and errcheck. I suggest using a private LibraryLoader in windows_helper, e.g.:

    windll = ctypes.LibraryLoader(ctypes.WinDLL)

Thanks. Here's the updated version. Also, I only tested it on Windows 8.1. I'll try to find another machine with an older OS for testing it.

Attached a new version of the patch which cleanups properly after tests.

Any type of feedback will be appreciated.

I'd like to see the windows_helper.py part of the patch split into its own issue, and someone more qualified than I to review it (though I'll learn what I can and give it a shot if nobody else can).  The new issue should also try to use the new windows_helper utilities to replace what Brian mentioned in msg106613 for os.symlink privileges, since that's an existing place where it can be used.

The actual change of adding UnloadKey looks fine to me, aside from a copy/paste error in the documentation (s/subkey to load/subkey to unload/).

Sure, that sounds good.

Here's the patch with only the change for winreg.UnloadKey. I'll have the patch with windows_helper soon.

Is there something I can do to move this forward?

The new patch drops the weird error dance from test_unload_key, it seems to work without it, I don't remember how it failed without it.

Ups, the last patch included an extra file.

The naming of the function needs discussion. I think it should be UnLoadKey, as the API function behind it is RegUnLoadKey (not RegUnloadKey). It may be illogical(*) that the function is called that way in the API, but it would add confusion if Python called it differently.

(*) It's UnlockFile that pairs LockFile, and UnmapViewOfFile that matches MapViewOfFile. OTOH, (undocumented) UTRegister is paired with UTUnRegister, and GlobalWire with GlobalUnWire.

Thank you for the review. The new patch uses the name UnLoadKey for the API.

Hello,

Can anyone review the last patch? Hopefully it is the final version, since the beta is really at the corner and I definitely would like to have this in 3.5.

I added an updated implementation of windows_helper.py to the dependency bpo-22080.