refs: read FETCH_HEAD and MERGE_HEAD generically

[git] / mergetools / smerge

diff_cmd () {
        "$merge_tool_path" mergetool "$LOCAL" "$REMOTE" -o "$MERGED"
}

merge_cmd () {
        if $base_present
        then
                "$merge_tool_path" mergetool "$BASE" "$LOCAL" "$REMOTE" -o "$MERGED"
        else
                "$merge_tool_path" mergetool "$LOCAL" "$REMOTE" -o "$MERGED"
        fi
}