Issue 3039: tarfile.TarFileCompat.writestr(ZipInfo, str) raises AttributeError (original) (raw)

tarfile.TarFileCompat.writestr( self, zinfo, bytes ) raises AttributeError("'ZipInfo' object has no attribute 'name'") because an analog to the tarfile.TarInfo.name attribute cannot be monkeypatched into the zinfo argument value when it's an instance of zipfile.ZipInfo.

The zipfile.ZipInfo class' attributes are slots, so no ad hoc attributes can be monkeypatched into an instance of it.

I've replaced the monkeypatching of zinfo with the creation of a new tarfile.TarInfo object, tinfo, which receives its relevant values instead.

This revealed another problem with the assignment of zinfo.file_size to tinfo.size: if zinfo.file_size has not been assigned a value then an AttributeError("file_size") will be raised because the slotted attribute doesn't exist. Being that the documentation for zipfile.ZipFile.writestr( self, zinfo_or_arcname, bytes ) claims that a zipfile.ZipInfo object value for zinfo_or_arcname must contain "at least the filename, date and time", it's highly likely that zinfo.file_size will be unassigned in ordinary use. I fixed this problem by ignoring the value of zinfo.file_size and using the value of len(bytes) instead, just like the implementation of zipfile.ZipFile.writestr.

I would have provided a patch for tarfile.TarFileCompat.writestr's unit test suite, but it doesn't appear to exist.