pycompat: explicitly prefix builtin attr usage with `builtins.`
It doesn't seem like this would fix any bug, because the wrapped functions that
take bytes instead of str are defined after these calls. But PyCharm was
flagging the second and third uses, saying "Type 'str' doesn't have expected
attribute 'decode'". It wasn't flagging the first, but I changed it for
consistency.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
Ensure that the username access fails gracefully if assumptions about the
environment made by python do not hold.
#if windows
>>> import os
>>> from mercurial import util
>>> os.environ.pop('LOGNAME', None) and None
>>> os.environ.pop('USER', None) and None
>>> os.environ.pop('LNAME', None) and None
>>> os.environ.pop('USERNAME', None) and None
>>> print(util.username())
None
#endif
$ cd ..