[merge "custom_merge_example_01"]
  name = "My custom merge driver example 01"
  # %A: current version
  # %O: ancestor version
  # %B: other branch version
  # must overwrite %A
  driver = /usr/local/chirayu/bin/custom_merge_example_01
  recursive = text

*/version  merge=custom_merge_example_01

#!/usr/bin/env zsh
CURRENT_FILE=$1
ANCESTOR_FILE=$2
REVISED_FILE=$3

# Figure out how to merge these / transform them in some way
# 
# REQUIRED: Final merge result must be in $CURRENT_FILE
#
# It's probably simple to fallback to or follow up with # (after
# your custom transformation) the "merge" tool to do the actual
# merge.  "merge" leaves behind conflict markers on conflicts and
# returns an error code (we'll pass along that same code.)
merge -A $CURRENT_FILE $ANCESTOR_FILE $REVISED_FILE
exit $?