File permission-related proposals
Once 6.10 is out of the way, we should file some permission-related proposals.
openBinaryTempFile mask the file permissions of the file they create with 0o600. However, we would like to use it for implementing things like
writeFileAtomic, in which case we want the default file permissions to be used.
System.Directory has an internal
copyPermissions function, but it should be exported.
This is not the same as
getPermissions s >>= setPermissions d as the Permissions type that the latter uses doesn't hold all the permissions info that we want.
Even better would be to make the Permissions type abstract, so that it /can/ contain all the info we want. Functions in the unix and Win32 packages would be able to do more with this type than the portable interface.