- Select all was selecting hidden elements
- Select flush was also selecting hidden elements (so selecting two *visible* vertices of a *hidden* edge selected that hidden edge)
- Several places were using BM_SetHFlag(elem, BM_SELECT) directly, when they should be using BM_Select(bm, elem)
- In certain scenarios, "reveal all" could leave you with selections which aren't valid in that selection mode (e.g. lonely edges selected in face select mode)