Copies are added after quickly dragging elements in the subgrid about gridstack.js

[v1talii-dev]

I roughly figured out the cause of the bug: at the dragging stage, an engine method is called, which adds a pseudo node to draw the future place for insertion. If you quickly move the mouse, a situation arises when nodes are added to the engine that should not be there. When a pseudo element is deleted, another method restores the original nodes, and there are duplicates in the original nodes. That is, the reason is the false filling of the original nodes.

https://github.com/gridstack/gridstack.js/blob/master/src/gridstack.ts#L2038

[v1talii-dev]

I think I managed to solve the problem. As you can see in pr, when quickly dragging, node does not appear:

And I don’t delete gridstackNode so that the engine’s addNode method works correctly and the duplicate is detected correctly.