tests/test-issue842

diffstat: made test case work with POSIX sh and printf

* arithmetic expression ((...)), without $, is bashism.
* printf '\xXX' seems non-standard. '\0' is okay.
  http://www.opengroup.org/onlinepubs/009695399/utilities/printf.html

tested with bash 4.0 and dash 0.5.5.1

#!/bin/sh

hg init test
cd test
echo foo > a
hg ci -Ama

hg up -r0000
echo bar > a
echo % should issue warning
hg ci -Amb

hg up -r0000
echo stuffy > a
echo % should not issue warning
hg ci -q -Amc

hg up -r0000
echo crap > a
hg branch testing
echo % should not issue warning
hg ci -q -Amd