On Sun, Aug 16, 2015 at 10:53:55AM +0100, Chris Lamb wrote: > Source: libcdio > Version: 0.83-4.2 > Severity: serious > Justification: fails to build from source > > Dear Maintainer, > > libcdio fails to build from source on unstable/amd64 under some > timezones (eg. TZ="/usr/share/zoneinfo/Etc/GMT-14"): > > [..] > /usr/bin/make check-TESTS [...] > FAIL: testiso9660 [...]
I have looked into this and there appear to be two problems. One is that the ISO9660 format, as far as I can see, still has no support for the GMT-14 time zone. It was introduced in 1995 and the limits in ISO9660 have not yet adapted, being restricted to GMT+12 and GMT-13. There probably needs to be special handling for GMT-14 to ignore test failure there as it seems inevitable. The other is that I *think* there are sign errors in the upstream time zone handling and therefore more time zones fail than should. | $ TZ=GMT+13 test/testiso9660 | ++ WARN: string 'ABC!123' is getting truncated to 2 characters | ++ WARN: Converted ISO 9660 timezone -52 is less than -48. Adjusted | $ TZ=GMT-13 test/testiso9660 | ++ WARN: string 'ABC!123' is getting truncated to 2 characters | ++ WARN: Converted ISO 9660 timezone -52 is less than -48. Adjusted | GMT offsets aren't equal. get: 46800, set 43200 | local time retrieved with iso9660_get_ltime() not | same as that set with iso9660_set_ltime(). As you can see both offsets get the westward 12 hour limit applied, probably in different functions using different signs. There are multiple time functions in lib/iso9660/iso9660.c and there is code like | #ifdef HAVE_TM_GMTOFF | /* Convert seconds to minutes */ | timezone = p_tm->tm_gmtoff / 60; | #else | timezone = (p_tm->tm_isdst > 0) ? -60 : 0; | #endif tm_gmtoff is seconds east of UTC and thus the offset to add. DST is also a positive offset but is given as a negative. The dtime function uses the sign of the passed timezone, the ltime function inverts it. Both limit the time zone value to -48 and 52. I'm not familiar with the intricacies of ISO9660 time values, but this needs a good looking over I think.
