code-dot-org/code-dot-org — pull request #718 by joshlory (2014-12-08 02:09:14+00:00)
Title: Keep grey blocks together when dragging, don't allow separation

I took a stab at implementing grouped grey blocks. When a grey block is dragged, the highest contiguous grey block (`topDraggingBlock`) is set as the drag target instead of the clicked block (`this`).

This blockly-core change feels risky to land before HoC.