The operator could crash in case the context "object" was overridden from python, but the "active_object" wasnt (and the active object was not a mesh). Reason for the crash is a mismatch in the operators poll function `data_transfer_poll` vs. `dt_layers_select_src_itemf` -- in the former, the overriden "object" was respected (and if this was a mesh, the poll was permissive), in the later it wasnt and only the "active_object" was used (if this was not a mesh, a crash would happen trying to get an evaluated mesh). Now rectify how the object which is used is being fetched -> use `ED_object_active_context` everywhere (see also rBe560bbe1d584). Maniphest Tasks: T96888 Differential Revision: https://developer.blender.org/D14552