Unselectable objects can be selected with Shift+click

[alidadasb]

Version

2.4.0

Test Case

https://jsfiddle.net/2sqzt51f/

Information about the environment

Nodejs or browser? Browser
Which browsers? Chrome

Steps to reproduce

// 1- click on blue circle
// 2- hold shift
// 3- click on red circle while holding the shift
// 4- click on the center of rect (somewhere on the green rect)
// 5- release the shift
// 6- you can move the none selectable rect.

Expected Behavior

Unselectable won't be selected

Actual Behavior

Unselectable will be selected in multiselection with shift

Apparently back in old days, this issue has been resolved 2460, however, since activeSelection implementation it has been broken again. The _shouldGroup checks the activeSelection object for the selectable flag, not the actual target.

[alidadasb]

Also, the onSelect and onDeselect on objects do not work in multi-select. Unless I'm mistaken, the expectation is to be able to override these methods to intercept the selection/deselection operation.

[asturur]

very weird, i may have broken it recently trying to simplify the code.
As i stated other times, till we have a way to test those interaction reliably there is always risk of breaking them

[asturur]

i do not think i fixed and verified also the onSelect and onDeselect