This is part of a fix for T88570, where the file selector would crash when activated multiple times.

Calling save multiple times would free the operator, leaving a dangling pointer which was used when panels were visible that accessed the "active_operator".

Noticed this when reviewing D13441, the steps to redo the crash are almost the same but it's a different bug.

To redo the crash with D13441 applied:

• Open Blender with the factory settings.
• Press Ctrl-S.
• N (to show the side-bar).
• Hold Ctrl-S, while doing so move the mouse between the root window and the file-selector.

Blender crashes P2930.