uu.py calls os.path.chmod which doesn't exist

[bsdphk]

BPO	33687
Nosy	@vstinner, @tiran, @bitdancer, @berkerpeksag, @vadmium, @serhiy-storchaka, @zhangyangyu, @timofurrer
PRs	bpo-33687: uu: fix call to os.chmod #7282 [3.7] bpo-33687: Fix call to os.chmod() in uu.decode() (GH-7282) #11592

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

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2019-01-17.14:35:37.533>
created_at = <Date 2018-05-29.22:02:07.813>
labels = ['3.7', '3.8', 'type-bug', 'library', 'easy']
title = "uu.py calls os.path.chmod which doesn't exist"
updated_at = <Date 2019-01-17.14:35:37.531>
user = 'https://bugs.python.org/bsdphk'

bugs.python.org fields:

activity = <Date 2019-01-17.14:35:37.531>
actor = 'berker.peksag'
assignee = 'none'
closed = True
closed_date = <Date 2019-01-17.14:35:37.533>
closer = 'berker.peksag'
components = ['Library (Lib)']
creation = <Date 2018-05-29.22:02:07.813>
creator = 'bsdphk'
dependencies = []
files = []
hgrepos = []
issue_num = 33687
keywords = ['patch', 'easy']
message_count = 18.0
messages = ['318119', '318151', '318286', '318293', '318810', '318814', '318815', '319208', '319211', '319273', '319275', '319276', '321552', '321554', '321557', '333871', '333874', '333875']
nosy_count = 9.0
nosy_names = ['vstinner', 'christian.heimes', 'r.david.murray', 'berker.peksag', 'martin.panter', 'serhiy.storchaka', 'bsdphk', 'xiang.zhang', 'tuxtimo']
pr_nums = ['7282', '11592']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue33687'
versions = ['Python 2.7', 'Python 3.7', 'Python 3.8']

[bsdphk]

Library file uu.py on at least 2.7 and 3.6 contains:

        try:
            os.path.chmod(out_file, mode)
        except AttributeError:
            pass

As far as I can tell, os.path.chmod does not exist, so this always raises AttributeError and becomes a no-op.

Is suspect the proper fix is to remove the ".path" ?

[serhiy-storchaka]

Looks as the proper fix to me.

[serhiy-storchaka]

Would be nice to add a test.

[timofurrer]

I've added a test and updated the PR.

[vstinner]

Is the uu module still maintained? Christian Heimes wants to remove the module:
https://github.com/tiran/peps/blob/oldbatteries/pep-9999.rst

Xiang Zhang made a change in uu last year to add a new feature: new backtick optional parameter, bpo-30103.

[bitdancer]

The email module uses it, so I would object to its being removed. It may not be used often (probably only when working with old email archives), but there's no good reason I can see to break something that currently works.

[zhangyangyu]

I modified it for the feature, not maintain it. I remember at that time I get the feeling it's somewhat strange there are two APIs, with similar functionality resides in two modules, need to be updated.

[vadmium]

What is your use case, Poul-Henning?

It looks like the module has never set the file mode, at least since it was added to Python in 1994. I suggest just remove the dead code and fix the documentation. At least you shouldn’t make this change in bug fix releases. It is just as likely to break people’s code as fix it.

If you do want to change the behaviour, I suggest using “os.open” to set the mode when the file is created. Otherwise you risk errors and messing up the filesystem when using special files e.g. uu.decode(..., "/dev/null").

[vstinner]

It looks like the module has never set the file mode, at least since it was added to Python in 1994. I suggest just remove the dead code and fix the documentation.

You cannot just remove the mode parameter without a deprecation period. Right now, the flag is documented:

https://docs.python.org/dev/library/uu.html
"mode is used to set the permission bits if the file must be created"

I agree with Martin that I am not comfortable to fix the bug in stable branches (2.7, 3.6, 3.7).

I'm +0 to fix the uu module in master (future 3.8).

If we fix the bug in master, we should document that mode is ignored in 2.7, 3.6 and 3.7 (update their documentation).

[bsdphk]

I was just playing with it in a prototype and noticed that it didn't work.