archive: set date to 1980 for very old zip files The zip file format stores the date using "MS-DOS format" which apparently means that they use 1980 as their epoch. Python's zipfile module emits deprecation warnings of this form /usr/lib/python2.6/zipfile.py:1108: DeprecationWarning: struct integer overflow masking is deprecated self.fp.write(zinfo.FileHeader()) /usr/lib/python2.6/zipfile.py:1108: DeprecationWarning: 'H' format requires 0 <= number <= 65535 self.fp.write(zinfo.FileHeader()) /home/mg/src/mercurial-crew/mercurial/archival.py:169: DeprecationWarning: struct integer overflow masking is deprecated self.z.close() /home/mg/src/mercurial-crew/mercurial/archival.py:169: DeprecationWarning: 'H' format requires 0 <= number <= 65535 self.z.close() when it is given such old timestamps. This fixes this by silently clamping the date to 1980.