[Python-Dev] os.path.getmtime on Windows

["Martin v. Löwis"]

Christian Tismer wrote:
> Does it mean that msvcrt does extra magic to modify the existing
> correct UTC entries? 

Mostly, yes. For FAT, the system does also some conversion.
Those conversions I don't fully understand,

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/file_times.asp

suggests that there are "cached UTC times" on FAT somewhere.

> And would usage of the Windows API heal this
> immediately, or are extra steps involved?

If we use GetFileTime, apparently yes. FindFirstFile apparently also
suffers from daylight conversion bugs when reading time stamps from FAT.

> As I understand the article, things are different when a file is
> stored in a FAT or NTFS drive.

Correct.

> Do you think the provided solution is worthwhile to be adapted
> for Python?
> http://www.codeproject.com/datetime/DstBugs/DstBugs.zip

No. If anything is done about this, it should be to drop msvcrt.

>> There are several issues involved in implementing such a patch, though.
>> One is that you need to do it twice: once for Win9x, and once for
>> NT+, because you have to use Unicode file names on one system, and
>> ANSI file names on the other.
> 
> 
> Correcting it just for NT/XP would make the majority of people
> happy, IMHO.

Right - the question would be whether completely breaking W9x support
in the process would be acceptable. We use the very same binaries
for W9x and NT.

Regards,
Martin