mergetools / tkdiffon commit blame: reject empty ranges -L,+0 and -L,-0 (5d57cac)
   1diff_cmd () {
   2        "$merge_tool_path" "$LOCAL" "$REMOTE"
   3}
   4
   5merge_cmd () {
   6        if $base_present
   7        then
   8                "$merge_tool_path" -a "$BASE" -o "$MERGED" "$LOCAL" "$REMOTE"
   9        else
  10                "$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
  11        fi
  12}