Saving an editor file while closing the related tab is broken

[Torsten Lilge]

Hi John,

after changeset http://hg.savannah.gnu.org/hgweb/octave/rev/27967cb3dea5
, saving a modified file while closing the related tab does not work
anymore. It seems, that now, where the sequential flow is partly
paralleled, the tab is removed before the thread crossing signal/slot
mechanism is completed (in this case: "do_save_file_signal" from
intergreter thread). Directly calling "do_save_file" from the
interpreter instead of emitting the related signal fixes the bug, but it
this safe?

Torsten