tests/test-rebuildstate

util: improved the check for the existence of the 'buffer' builtin

2to3 is unable to translate '__builtin__' calls to 'builtins' when
hasattr is used (as in hasattr(__builtin__, buffer)). Translating the
check to the format

try:
    whatever
except NameError
    # define whatever
    __builtin__.whatever = whatever

is a correct way of checking for the name and has the benefit of being
translated by 2to3. This patch implements the same idea for the
aforementioned example.

#!/bin/sh
# basic test for hg debugrebuildstate

hg init repo
cd repo

touch foo bar
hg ci -Am 'add foo bar'

touch baz
hg add baz
hg rm bar

hg debugrebuildstate
echo '% state dump after'
hg debugstate --nodates | sort
echo '% status'
hg st -A