Original bug ID: 7569
Reporter: markghayden
Assigned to: @gasche
Status: resolved (set by @gasche on 2017-06-27T02:01:00Z)
Resolution: duplicate
Priority: normal
Severity: minor
Platform: AMD64
OS: MacOS
OS Version: 10.12.2
Version: 4.04.0
Fixed in version: 4.04.2
Category: otherlibs
Duplicate of: #7385

Bug description

stat.c in otherlibs/win32unix has the following code for converting file times:

if (!FileTimeToLocalFileTime(time, &local) ||
    !FileTimeToSystemTime(&local, &sys))

The MSDN docs (https://msdn.microsoft.com/en-us/library/windows/desktop/ms724277%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396) say the following:

Remarks

To account for daylight saving time when converting a file time to a local time, use the following sequence of functions in place of using FileTimeToLocalFileTime:
FileTimeToSystemTime
SystemTimeToTzSpecificLocalTime
SystemTimeToFileTime

Steps to reproduce

0. Get current time with Unix.gettimeofday
1. Create a file
2. Call Unix.stat
3. Compare stat.st_mtime with the gettimeofday

See attached test file.

Additional information

Output on MacOS is correct:

time0 =1498527385.21647906
time0a=1498527385.00000000 (-0.21647906)
time1 =1498527385.00000000 (-0.21647906)
time2 =1498527385.21670294 (+0.00022388)

Output on Windows is incorrect:

time0 =1498528190.84126230
time0a=1498528190.00000000 (-0.84126234)
time1 =1498513790.00000000 (-14400.84126234) <<<<<<<<<<<<<<<<<<<<
time2 =1498528190.84126230 (+0.00000000)

File attachments

• stat_error.ml