This test fails because in *NIX when the umask is 0027, files are created with 0640 permissions. The current implementation of Zip::File.create_file_permissions does a simple subtraction of 0666 - 0027 == 0637
Instead of inheriting the permissions from the tmp directory, new files should
have permissions that reflect the defaults on the system taking umask into
account.
It seems that (unix) permissions of 666 - umask are as close to a standard as
anything [1] and that 'touch' uses this. On Windows it seems sensible to just
use 644 directly [2].
[1] http://unix.stackexchange.com/a/102080
[2] http://ruby-doc.org/core-1.9.3/File.html
Robert Haines
Takumasa Ochi
Marcos Wright-Kuhns