Deleted layers/blocks not tracked correctly

[Patrick Martin]

Version: 2.1.3
Compiler: GNU GCC 4.9.1
Compiled on: Sep 23 2016
Qt Version: 5.4.1
Boost Version: 1.60.0
System: Windows 7

I have seen this error with both blocks and layers. When you delete an item from the block or layer grid, the item is removed from the display but the name of the item is still referenced in the underlying list data. The result is that the items in the grid may be pointing to incorrect items in the underlying list data.

For example, create a block named "Block A", delete the block, then try to create another block named "Block A".

I have seen instances where I will delete a layer called "Layer A" and nothing will happen, or else I will get a popup dialog warning me that I am about to delete a layer of a different name. I suspect this is related to the overall issue of collections getting out of sync with the GUI controls they are bound to.

This bug causes unpredictable behavior when copying/moving between layers, deleting entities, deleting blocks or deleting layers.