tests/test-merge8

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

# Test for changeset ba7c74081861
# (update dirstate correctly for non-branchmerge updates)
hg init a
cd a
echo a > a
hg add a
hg commit -m a
cd ..
hg clone a b
cd a
hg mv a b
hg commit -m move
echo b >> b
hg commit -m b
cd ../b
hg pull ../a
hg update