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On 10 Feb 2009, at 12:28, Guilherme Polo wrote:
>
> Guilherme Polo <ggpolo@gmail.com> added the comment:
>
> Wouldn't it be better if you only ignored the 'illegal seek' error
> instead of ignoring any ioerror (should it even be always discarded) ?
No.
> I
> get a 'bad file descriptor' under Windows 7, but, again, can it be
> always discarded ?
Yes.
To expand: Observe that the exception is raised when we are writing 
the header for the first time. The exception is not raised when we 
attempt to seek to patch the header, it is raised when we recording 
the file position so that we can seek to it later.
We record the file position even though we might not use it later 
(the file position is only needed if we need to patch the header).
So if we don't need to patch the header, we do not need the file 
position. So we can clearly ignore any error in attempting to get 
the file position.
If we do need to patch the header, then we need the file position. 
If we do not have the file position (because the earlier attempt to 
get it failed), then patching the header will fail when it attempts a 
seek. This seems reasonable to me.
>
> You can also reproduce the problem without using wave:
>
>>>> import sys
>>>> sys.stdout.tell()
That does not reproduce the problem. The problem is not that tell 
raises an exception, the problem is that tell raises an exception and 
it is only being used to get some information that may be not needed 
later. Therefore the exception should be ignored, and a problem 
should only be raised if it turns out that we did need for 
information that we couldn't get.
>
> I'm really unsure about the proposed patch.
Noted.
I also note that my patch can be improved by removing its last 11 lines.