Windows getpass bug

[amc1]

BPO	546558
Nosy	@tim-one, @mhammond, @birkenfeld

^{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/mhammond'
closed_at = <Date 2008-01-20.13:54:49.060>
created_at = <Date 2002-04-20.18:34:10.000>
labels = ['OS-windows']
title = 'Windows getpass bug'
updated_at = <Date 2008-01-20.13:54:49.058>
user = 'https://bugs.python.org/amc1'

bugs.python.org fields:

activity = <Date 2008-01-20.13:54:49.058>
actor = 'georg.brandl'
assignee = 'mhammond'
closed = True
closed_date = <Date 2008-01-20.13:54:49.060>
closer = 'georg.brandl'
components = ['Windows']
creation = <Date 2002-04-20.18:34:10.000>
creator = 'amc1'
dependencies = []
files = []
hgrepos = []
issue_num = 546558
keywords = []
message_count = 6.0
messages = ['10452', '10453', '10454', '10455', '58701', '61289']
nosy_count = 5.0
nosy_names = ['tim.peters', 'mhammond', 'amc1', 'georg.brandl', 'JosephArmbruster']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue546558'
versions = []

[amc1]

I'm currently running Python 2.2.1 on a Windows 98
box, and this is the code I have just run.

-------

Python 2.2.1 (#34, Apr  9 2002, 19:34:33) [MSC 32 bit 
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for 
more information.
>>> import getpass
>>> def x():
...    secret = getpass.getpass('Tell me a secret: ')
...    stuff = raw_input ('Tell me something else: ')
...    print 'The user told me the secret was "%s" and 
the other thing was "%s"'
 % (secret, stuff)
...
>>> x()
Tell me a secret:
Tell me something else:
The user told me the secret was "Autechre" and the 
other thing was ""
>>>

---

This may seem normal, but I didn't get the opportunity
to enter anything when the raw_input was called. I'm
assuming that getpass leaves the newline character in
the input buffer, which is then used by raw_input,
leaving you unable to enter anything.

[tim-one]

Logged In: YES
user_id=31435

Assigning to MarkH in case he has a bright idea. I don't.

The problem is that getpass on Windows is implemented via
raw Windows console I/O, and console I/O buffers interact
in strange and undocumented ways with C's stdio buffers.
I've never found a reliable way to keep them in synch, and
MS says you can't mix the two, period. The only workaround
I know of is to build your own raw_input() workalike out of
the msvcrt module's console I/O routines (getch(), etc).

[amc1]

Logged In: YES
user_id=39733

I've currently written a module which attempts to fix this
problem, which you can get from here:
http://ccec.sf.net/getpassfix.html

However, as I've mentioned in the documentation, it is a hack,
but the "platform" based solution should become a more
suitable candidate as it is tested.

[amc1]

Logged In: YES
user_id=39733

The function getpass_hack in the getpassfix module
(referenced earlier) is a suitable alternative to the win_getpass
function in the getpass module, but it should only be used if
the operating system is Windows 95/98/ME (this is based on
my observations so far).

If we have a nice Pythonic way of determining what operating
system that Python is running on (say, by using Marc-Andre
Lemburg's platform module:
http://www.lemburg.com/files/python/platform.py), we could
then provide a straightforward fix.

[JosephArmbruster]

For the record, I tested this out with:

url: http://svn.python.org/projects/python/branches/py3k:
rev: 59540
OS Name: Microsoft Windows XP Professional
OS Version: 5.1.2600 Service Pack 2 Build 2600

The following snippet appeared to behave as intended (i input "secret"
them "something else"):

>>> import getpass
>>> def x():
...    secret = getpass.getpass('Tell me a secret: ')
...    stuff = input('Tell me something else: ')
...    print('The user told me the secret was "%s" and the other thing
was "%s"' % (secret, stuff))
...
>>> x()
Tell me a secret:
Tell me something else: something else
The user told me the secret was "secret" and the other thing was
"something else
"
>>>

[birkenfeld]

So it seems to be fixed in NT -- we don't support 9x anymore in 2.6 up.