contrib/win32/hg.bat

tests: change blackbox test to work cross platform

While it is not easy to make a file 000 on Windows, you can
emulate most of the behaviors by replacing the file with a directory.

Also corrects test description to properly indicate that failing to
read from the log is fatal.

@echo off
rem Windows Driver script for Mercurial

setlocal
set HG=%~f0

rem Use a full path to Python (relative to this script) if it exists,
rem as the standard Python install does not put python.exe on the PATH...
rem Otherwise, expect that python.exe can be found on the PATH.
rem %~dp0 is the directory of this script

if exist "%~dp0..\python.exe" (
    "%~dp0..\python" "%~dp0hg" %*
) else (
    python "%~dp0hg" %*
)
endlocal

exit /b %ERRORLEVEL%