bdist_wininst depends on MBCS codec, unavailable on non-Windows

[merwok]

BPO	10945
Nosy	@loewis, @amauryfa, @vstinner, @tarekziade, @merwok, @jelmer, @hroncok, @miss-islington
PRs	python/cpython#14506 python/cpython#14509 python/cpython#14510

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields: ```python assignee = 'https://github.com/merwok' closed_at = created_at = labels = ['type-bug', 'library'] title = 'bdist_wininst depends on MBCS codec, unavailable on non-Windows' updated_at = user = 'https://github.com/merwok' ``` bugs.python.org fields: ```python activity = actor = 'vstinner' assignee = 'eric.araujo' closed = True closed_date = closer = 'vstinner' components = ['Distutils', 'Distutils2'] creation = creator = 'eric.araujo' dependencies = [] files = [] hgrepos = [] issue_num = 10945 keywords = ['patch'] message_count = 27.0 messages = ['126528', '126531', '126533', '126536', '126539', '135892', '135894', '139968', '139974', '145213', '145509', '145540', '145548', '145627', '145630', '145680', '155591', '155603', '346998', '346999', '347001', '347009', '347011', '347013', '347015', '347132', '384814'] nosy_count = 12.0 nosy_names = ['loewis', 'amaury.forgeotdarc', 'vstinner', 'techtonik', 'tarek', 'eric.araujo', 'Arfrever', 'jelmer', 'runtux', 'hroncok', 'Jelmer Vernooij', 'miss-islington'] pr_nums = ['14506', '14509', '14510'] priority = 'normal' resolution = 'wont fix' stage = 'resolved' status = 'closed' superseder = None type = 'behavior' url = 'https://bugs.python.org/issue10945' versions = ['3rd party', 'Python 2.7', 'Python 3.2', 'Python 3.3'] ```

[merwok]

If distutils.commands.bdist_wininst.bdist_wininst.get_inidata returns a unicode string (which is always the case in 3.x and can happen in 2.x if if you pass a unicode object as one setup argument), bdist_wininst will try to use the MBCS codec, which is not available on non-Windows OSes (see http://docs.python.org/dev/library/codecs#module-encodings.mbcs).

If someone wants to make a patch, here are some guidelines: http://wiki.python.org/moin/Distutils/FixingBugs

[9432cd65-9f88-4bc6-8ad6-72e5ab1c730d]

I believe it is better to start and commit a testcase .

[merwok]

We don’t commit failing tests :) If you mean you want to write a test case, please go ahead and attach a patch or changeset URI.

[9432cd65-9f88-4bc6-8ad6-72e5ab1c730d]

Please don't ask me about patches. Core devs won't accept them.

[merwok]

Please don't ask me about patches. Core devs won't accept them.

One of your patches for diff has been accepted; some distutils bugs have patches from you (for which we are grateful) that are in various review stages. The only thing preventing acceptance where I’m concerned is time, nothing else.

[045f8f0d-9bfc-4a14-9319-6b326ddadb21]

I've just been bitten by this when trying to do a new release of roundup, why not make the mbcs codec available on non-windows platforms as has been proposed (and rejected) in bpo-1251921 -- any non-technical reasons for not including this codec on other platforms?

[amauryfa]

The mbcs codec depends on the Windows installation. On most Western Windows it is similar to cp1252, Japanese Windows will use cp932, and so on. If we were to provide mbcs on non-windows platform, it should be an alias to ascii.

[vstinner]

Can't you only work with Unicode and avoid the MBCS encoding?

[045f8f0d-9bfc-4a14-9319-6b326ddadb21]

On Thu, Jul 07, 2011 at 10:52:51AM +0000, STINNER Victor wrote:

Can't you only work with Unicode and avoid the MBCS encoding?

I'm trying to build a windows binary package on Linux. This usually works fine -- as long as the package description doesn't contain unicode. If it *contains* unicode it will somehow internally use MBCS encoding. So if someone fixes windows binary package building on non-windows platforms to not use MBCS encoding this is fine with me. But maybe the easier way out here is to include that codec on all platforms.

(and don't tell me I have to install windows for building a windows binary package :-)

Thanks, Ralf -- Dr. Ralf Schlatterbeck Tel: +43/2243/26465-16 Open Source Consulting www: http://www.runtux.com Reichergasse 131, A-3411 Weidling email: office@runtux.com osAlliance member email: rsc@osalliance.com

[merwok]

haypo:

Can't you only work with Unicode and avoid the MBCS encoding? It is not code under the users’ control (i.e. setup.py) that uses MBCS, but the bdist_wininst command itself. It used to be runnable from linux, which is great to provide binary installers for Windows users who typically don’t have a compiler. This is what the bug is about.

[vstinner]

It is not code under the users’ control (i.e. setup.py) that uses MBCS, but the bdist_wininst command itself.

bdist_command append configuration data to a wininst-xxx.exe binary. Where does this file come from? Can we modify wininst-xxx.exe binaries?

If we can modify the binaries, we can change the format to store the configuration data as UTF-8 instead of the ANSI code page.

It's surprising and "unsafe" (not portable) to use the ANSI code page for an installer: if you build your installer on a french setup (ANSI=cp1252), the configuration was be interpreted incorrectly on a japanese setup (ANSI=cp932). Example:

>>> 'Hé ho'.encode('cp1252').decode('cp932')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'cp932' codec can't decode bytes in position 1-2: illegal multibyte sequence

So if the configuration data (package metadata) contains non-ASCII characters, you will not be able to use your installer on a computer using a different ANSI code page than the code page of the computer used to build the installer... In the best case, you will just get mojibake.

If we cannot modify wininst-xx.exe, an alternative to be able to generate installers on non-Windows platforms is to use the most common ANSI code page (cp1252?), or maybe ASCII.

Use the ASCII encoding is the safest solution because you will be able to use your installer on all Windows setup (all ANSI code pages are compatible with ASCII), but you will not be able to generate an installer if the package metadata contains at least one non-ASCII character...

[merwok]

> It is not code under the users’ control (i.e. setup.py) > that uses MBCS, but the bdist_wininst command itself. bdist_command append configuration data to a wininst-xxx.exe binary. Are you sure? The string that’s encoded with mbcs comes from the get_inidata method in bdist_wininst.py; get_inidata only works with strings (either string literals or str objects (in 3.x) given as attributes of the command object or in the DistributionMetadata object).

Where does this file come from? Can we modify wininst-xxx.exe binaries? If needed, we can: the code lives in PC/bdist_wininst.

Use the ASCII encoding is the safest solution I don’t think so. Distutils supports author='Éric', so bdist_wininst should too :)

[61337411-43fc-4a9c-b8d5-4060aede66d0]

The problem is that the config file is parsed using GetPrivateProfileString, and the result is then passed to TextOut, SetDlgItemText, CreateWindow, etc. all of which are defined to accept MBCS strings. I agree that this can't work correctly in the general case.

Changing the GUI functions to operate on Unicode strings is certainly feasible and a good idea. The main challenge then is the format of the INI file. IIUC, GetPrivateProfileStringW is willing to process UTF-16 (with BOM) encoded INI files, but I never tested whether it actually does. If it does, I recommend to have the INI file encoded in UTF-16 (with BOM, using LE for safety).

In porting wininst.exe, it seems tempting to use the TEXT family of APIs. I'd advise against that, and recommend to explicitly use the *W functions.

[vstinner]

The problem is that the config file is parsed using GetPrivateProfileString, and the result is then passed to TextOut, SetDlgItemText, CreateWindow, etc. all of which are defined to accept MBCS strings. I agree that this can't work correctly in the general case.

These functions are available with an Unicode API:

GetPrivateProfileStringW TextOutW SetDlgItemTextW CreateWindowW ...

Changing the GUI functions to operate on Unicode strings is certainly feasible and a good idea. The main challenge then is the format of the INI file. IIUC, GetPrivateProfileStringW is willing to process UTF-16 (with BOM) encoded INI files, but I never tested whether it actually does.

bdist_wininst creates a long Unicode string for the INI data, and then encode it explicitly:

        if isinstance(cfgdata, str):
            cfgdata = cfgdata.encode("mbcs")

So I suppose that replacing "mbcs" by "UTF-16-LE" and add the BOM should be enough.

In porting wininst.exe, it seems tempting to use the TEXT family of APIs. I'd advise against that, and recommend to explicitly use the *W functions.

Do we need to keep backward compatibility if we change the format of the config data? Or wininst-xx.exe are only usable with trailing config data in the .exe file?

[61337411-43fc-4a9c-b8d5-4060aede66d0]

Do we need to keep backward compatibility if we change the format of the config data? Or wininst-xx.exe are only usable with trailing config data in the .exe file?

The wininst.exe belongs to the version of distutils it is released with. So if we change both consistently, no backwards-compatibility problems arise.

[merwok]

Would the proposed change mean that a bdist_wininst built with 3.2.0 won’t work with a patched 3.2.3?

[merwok]

The proposition of using other C functions and changing the bdist_wininst code looks risky to me, especially as I don’t know how compatibility would be affected (see my previous message). We are free to improve the wininst code in distutils2, or discuss a replacement (Jeremy Kloth was working on something with all the features of MSI and wininst), but for distutils I would very much prefer the simplest fix that could possibly works.

bdist_msi decodes data read from setup.py with MBCS on Windows; on other OSes, couldn’t the locale preferred encoding be used?

[vstinner]

Would the proposed change mean that a bdist_wininst built with 3.2.0 won’t work with a patched 3.2.3?

The installer doesn't use distutils to read its configuration, so such binary runs with any installed Python version.

bdist_msi decodes data read from setup.py with MBCS on Windows; on other OSes, couldn’t the locale preferred encoding be used?

It would be worse: Linux doesn't use Windows code page. Most modern OSes are now using UTF-8 locale encoding, whereas Windows never use UTF-8 as the ANSI code page.

[bc75918c-a209-4fa3-b6cf-28cfb7317f76]

I've opened a PR thet removes the support for bdist_wininst on non-Windows. Apparently, it was broken since the beginning of Py3k anyway. The support can be reintroduced once it is actually fixed (or never).

https://github.com/python/cpython/pull/14506

[vstinner]

I've opened a PR thet removes the support for bdist_wininst on non-Windows. Apparently, it was broken since the beginning of Py3k anyway. The support can be reintroduced once it is actually fixed (or never).

It would be better to use the Unicode (wide character) flavor of the Windows API to avoid completely any explicitly encoding, and only pass Unicode strings. But This issue is open for 8 years and it seems like nobody cares enough to invest time to implement such change.

So I'm fine with trivial PR 14506. It doesn't change the status quo: bdist_win was always broken on non-Windows platforms since Python 3.0, but the PR makes the status quo more obvious which is a good thing.

[vstinner]

I started a discussion on the Packaging list:

"Deprecate bdist_wininst" https://discuss.python.org/t/deprecate-bdist-wininst/1929

[vstinner]

New changeset 72cd653c4ed7a4f8f8fb06ac364b08a97085a2b5 by Victor Stinner (Miro Hrončok) in branch 'master': bpo-10945: Drop support for bdist_wininst on non-Windows systems (GH-14506) https://github.com/python/cpython/commit/72cd653c4ed7a4f8f8fb06ac364b08a97085a2b5

[miss-islington]

New changeset 45c10da40912e04c0d0de02af4b23438ed0de49b by Miss Islington (bot) in branch '3.7': bpo-10945: Drop support for bdist_wininst on non-Windows systems (GH-14506) https://github.com/python/cpython/commit/45c10da40912e04c0d0de02af4b23438ed0de49b

[miss-islington]

New changeset be5bb52f5f2d4da4b9d6f42399f7275ab47910f3 by Miss Islington (bot) in branch '3.8': bpo-10945: Drop support for bdist_wininst on non-Windows systems (GH-14506) https://github.com/python/cpython/commit/be5bb52f5f2d4da4b9d6f42399f7275ab47910f3

[vstinner]

Follow-up issue: bpo-37468 "Don't install wininst*.exe on non-Windows platforms".

[vstinner]

Lib/distutils/tests/test_bdist_wininst.py contains an interesting comment linking to bpo-5731:

        # bpo-5731: command was broken on non-windows platforms
        # this test makes sure it works now for every platform
        # let's create a command

Related commit:

commit ad95826c33ea378db2807a268363ccfbf0ea8273 Author: Tarek Ziadé \ziade.tarek@gmail.com\ Date: Thu Apr 9 21:36:44 2009 +0000

Fixed bpo-5731: Distutils bdist_wininst no longer worked on non-Windows platforms

But there is also bpo-8954 follow-up which is still open: "wininst regression: errors when building on linux".

[vstinner]

The distutils bdist_wininst command has been removed in Python 3.10: see bpo-42802.