use of with_saved_back_trace?

[Hoehle, Joerg-C. <Joe...@t-...>]

Hi,

trying to investigate the hairy foreign-call-in bug, I wonder whether the callback() call-in would benefit from a with_saved_back_trace().

Beside showing up nicely in back traces, is it required for anything?
CLISP only seems to use it when some SUBR calls another SUBR.

I remember (from 10 yeargs ago) CMUCL reported
"foreign land" ...
among its backtrace when callbacks where involved.  It was valuable to see.

Regards,
	Jorg Hohle.