git-mergetool-batch

echo off

REM PARAMS: $BASE $LOCAL $REMOTE $MERGED

set base=%1
set local=%2
set remote=%3
set merged=%4

set nul="nul"

set emptyfile="%userprofile%/.empty"

set p4mergepath="c:/program files/perforce/p4merge.exe"

if "%local%" == "%nul%" (
    set local=%emptyfile%
)

if "%remote%" == "%nul%" (
    set local=%emptyfile%
) 

call %p4mergepath% %base% %local% %remote% %merged%