Fix object removal with custom code

[nurbs999]

If objects get removed by custom code like this

fabric.Canvas.prototype.customiseControls({
    tr: {
        action: function( e, target ) {
            // bugfix for text elements in fabric
            let canvas = target.canvas;

            if (canvas.getActiveObject()) {
                canvas.remove(canvas.getActiveObject());
            }
            target.canvas = canvas;

            canvas.deactivateAll();
            canvas.renderAll();
            // do other important stuff after object was removed
        }
    }
}, function() {
});

fabricjs crashed because action is a function in this case.

[asturur]

i can accept action.slice && action.slice(...) actions functions are not part of fabric and i do not want to make it looks like they are.

[nurbs999]

That will also work. I would really appreciate if you could make this change.
if (action.slice && action.slice(0, 5) === 'scale') {

[asturur]

can't you just do in this PR?

[nurbs999]

I changed the PR with the new commit.
I just have little experiance with PRs. How do I submit my PR to your master branch?

[asturur]

that's ok

[asturur]

be carefull that this is submitted to master branch and backported to 1.x

If you want to use this fix NOW or you add manyally to your build or you build from the 1.x branch.
I'll publish this fix and another fix in fabric 1.7.13 as soon as i have some time

[nurbs999]

Thanks a lot.
I manually fixed this in my current dest build, too.