[Twisted-Python] Re: plus mode was Re: how winnt fileops workand what to do about it

[Jean-Paul Calderone]

On Sat, 31 Dec 2005 18:12:06 -0500, James Y Knight <foom at fuhm.net> wrote:
>
>On Dec 31, 2005, at 4:57 PM, Paul G wrote:
>>oh, it makes perfect sense to have a workaround in twisted, i'm not 
>>suggesting otherwise. however, it should be just that - a temporary 
>>workaround until cpython has a fix for the issue, because (outside  of the 
>>offending libc implementation), that is the right place to  fix it.
>
>As I wrote in the bug report:
>>It's not a python bug except perhaps that python should raise an 
>>exception.
>>Doing a read and write without a seek in between is illegal in C.
>>
>>"ANSI C requires that a file positioning function intervene between  output 
>>and
>>input, unless an input operation encounters end-of-file."
>
>I am against including any sort of workaround besides raising an  exception 
>if the situation occurs. And I don't think even that is  particularly 
>warranted.

Thanks for pointing this out.  The immediate fix is now obvious: the test needs to change.  It _might_ be nice to have an assertion for this behavior, but I'm not about to add a file wrapper just for this (if all of Twisted used FilePath, instead of opening files directly, I might grant more weight to this, but since it doesn't...).

Jean-Paul