Re: [boost] [filesystem] Failures on FAT32

From: Beman Dawes (bdawes_at_[hidden])
Date: 2004-10-08 15:18:27

At 12:18 PM 10/8/2004, Stefan Slapeta wrote:
 >Hi all,
 >
 >there are two failures reported for the intel-win32-8.1 toolset (both in
 >operations_test): http://tinyurl.com/5dbla
 >
 >After some investigation I've found out now that the tests fail only
 >because they are run on a FAT32 disk! It was just coincidence that the
 >failures popped up in the Intel 8.1 tests (...and it's quite amusing to
 >say that we would need another toolset dimension for the filesystem :) )

These same two failures have also shown up on some other platforms from 
time-to-time. There is apparently a new debug mode assert in VC++ 8.0 which 
is firing due to the second error.

 >Anyway, here some analysis (the second failure seems to be a general
 >design problem!):

The second error is actually a really stupid typo in my original code that 
just happens to result in valid C++ that compiles (but does the wrong 
thing). I must have looked at that code five times in the last year, but 
didn't spot the typo until I read your message. See below.

 >First failure:
 >
 >operations_test.cpp(287): test time_diff >= 0.0 && time_diff < 60.0 
failed
 >
 >--> the actual difference is -2!

I'll change the test to plus or minus 60 seconds.

 >Second failure:
 >
 >std::exception: boost::filesystem::last_write_time
 >("wrong parameter")
 >
 >last_write_time contains this code:
 >
 >       ::utimbuf buf;
 >       buf.actime = std::time_t();
 >                    ^^^^^^^^^^^^^

That was meant read:

         buf.actime = std::time(0)

(The same typo appears later in the code, too.)

Now, it may be a poor design to update actime to the current time. It might 
be better to do a stat(), and get st_atime, and then use that. Opinions?

Thanks,

--Beman