Block comment by inserting (instead of changing) lines?

[goulf-3m]

For example, the following line:

    x=x*2;
    return x;

After gb with this plugin, both lines are changed:

    /* x=x*2;
    return x; */

This is bad for tracking code with Git. It would be better to block comment by inserting lines and preserving existing lines, like this:

    /*
    x=x*2;
    return x;
    */