bug#45277: D-Bus crashes and DND errors

[Juri Linkov]

> Do you have a recipe how to provoke this error?

After dbus-handle-event started to pull random parts of the init file
to use as its event arg, I realized that something is wrong with the build,
made clean bootstrap, and D-Bus problems went away.  Sorry for false alarm.

The second part of this bug report was about DND errors, that
is unrelated to D-Bus, but DND errors should be fixed anyway.

Here's a test case for DND errors:

Eval:
(modify-frame-parameters nil '((undecorated . t)))
(toggle-frame-maximized)

(frame-parameter nil 'left)
=> (+ -1)

Since it's not a number, x-dnd-handle-xdnd signals the error:

  Bad data in VALUES, must be number, cons or string