fix(options): reject restricted assignments before parsing callbacks

Problem:
A restricted option assignment parses its callback before
rejecting the change. A Syntax handler triggered by a modeline can
therefore evaluate bound arguments even though the option cannot be
changed.

Introduced by 726d1a92d2. That change moved callback construction
from did_set_operatorfunc(), after the permission check, into validation
and storage, before did_set_option() checks permissions.

Solution:
Check permissions before parsing the callback, preserving the
existing option value without evaluating the rejected expression.

AI-assisted

0 files changed, 0 insertions, 0 deletions