Problem was that the event was not `NULL` even though the `context` is `WM_OP_EXEC_*`. I noticed this problem when dropping .blend files into Blender. Instead of only executing `WM_OT_open_mainfile`, it was invoked (opening a file selector). The `wm_operator_invoke`, which also executes operators, always invokes operators when `event != NULL`. So setting `event` to `NULL` tells `wm_operator_invoke` not to invoke but to execute the operator. Reviewers: brecht Differential Revision: https://developer.blender.org/D3799