Update method breaks default drag and drop behavior for subgrids #3173

Subject of the issue

When calling Gridstack.update(), with the exact same values the node already has, the _orig value is cleared out (added as part of #2669). This breaks the implementation of GridStack.prepareDragDrop#onEndMoving, as the widthChanged variable requires the _orig property to exist on the GridStackNode.

Moving the element within its parent grid repopulates the _orig property again, allowing the drag and drop to work.

This is normally not an issue unless the user drags an element off the grid without touching/moving an existing element (such as the case when float = true). Then, the _orig parameter is never restored and dragging to a subgrid fails.

Your environment

VueJS 3.5, Using GridStack 12.3.2.

Steps to reproduce

Using the demo at https://github.com/gridstack/gridstack.js/blob/master/demo/nested.html, simply add a call to grid.update('.grid-stack-item:first-of-type', {x: 0, w: 1, y: 0, h: 1}) twice. The first time will assign the 4 parameters to the node, the second time will do nothing but clear the _orig parameter.

You can do this in the debugger console on the existing demo as well.

Expected behavior

Update should leave the widget in the correct state, even if a redundant update call was issued. Without this, the node will drag/drop within its own grid properly, but cannot be dragged outside of its grid.

Workaround

As a dirty workaround, we can do the same thing the Engine class is doing and assign the _orig parameter ourselves like so: