winsound.PlaySound() with SND_MEMORY should accept bytes instead of strings

[TomFelker]

BPO	11620
Nosy	@pfmoore, @irmen, @tjguk, @briancurtin, @ericsnowcurrently, @zware, @zooba
Files	11620-PlaySound.patch: Patch to fix SND_MEMORY flag for winsound.PlaySound issue11620.diff

^{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:

assignee = 'https://github.com/zware'
closed_at = <Date 2016-09-05.21:32:12.296>
created_at = <Date 2011-03-21.00:34:40.499>
labels = ['extension-modules', 'type-bug', 'OS-windows']
title = 'winsound.PlaySound() with SND_MEMORY should accept bytes instead of strings'
updated_at = <Date 2016-09-05.21:35:45.296>
user = 'https://bugs.python.org/TomFelker'

bugs.python.org fields:

activity = <Date 2016-09-05.21:35:45.296>
actor = 'zach.ware'
assignee = 'zach.ware'
closed = True
closed_date = <Date 2016-09-05.21:32:12.296>
closer = 'python-dev'
components = ['Extension Modules', 'Windows']
creation = <Date 2011-03-21.00:34:40.499>
creator = 'Tom.Felker'
dependencies = []
files = ['24470', '44104']
hgrepos = []
issue_num = 11620
keywords = ['patch']
message_count = 8.0
messages = ['131583', '152985', '198748', '260236', '271948', '272691', '274435', '274437']
nosy_count = 11.0
nosy_names = ['paul.moore', 'irmen', 'tim.golden', 'tlesher', 'brian.curtin', 'sijinjoseph', 'python-dev', 'Tom.Felker', 'eric.snow', 'zach.ware', 'steve.dower']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue11620'
versions = ['Python 3.6']

[TomFelker]

PlaySound supposedly lets you play a .WAV file whose contents are stored in a string, by passing the string and flags including winsound.SND_MEMORY. I'm trying to use BytesIO object and the wave module to make a file in-memory, and pass this to winsound. It's a TypeError if I pass the resultant bytes object directly, and if I pass a string object, I get

TypeError: must be str without null character or None, not str

Since wav files can contain zeros, for the feature to work at all, the C code would need to detect the SND_MEMORY flag and interpret the first argument as a bytes object, instead of a null-terminated string, in that case.

[tlesher]

This patch should both correct the incorrect acceptance of strings and the incorrect rejection of buffer objects when using SND_MEMORY.

[ericsnowcurrently]

I ran into this today. Can't we just change the "Z" to "z#" in the format string (or "z*")? Other than that, Tim's patch makes sense.

[irmen]

Ran into this today when trying to provide a fallback sound output on windows when the user hasn't got pyaudio installed.
It seems that this module has been forgotten and didn't get fixed when the str/bytes change happened in Python 3.0?

[zware]

Irmen, you're probably correct that this was overlooked at the time of 3.0.

The patch is well out of date as well, winsound was Clinicized around the 3.4 timeframe.

[zware]

Here's an updated patch. I'm a little wary of applying this on 3.5, because it is backward-incompatible: a str is no longer accepted with SND_MEMORY. On the other hand, it's pretty much a fluke if that works at all currently.

[python-dev]

New changeset 8fa615a2a896 by Zachary Ware in branch 'default':
Closes bpo-11620: Fix support for SND_MEMORY in winsound.PlaySound.
https://hg.python.org/cpython/rev/8fa615a2a896