Indeed, it shouldn't, but the question is: what code is responsible
for that which shouldn't happen? If some package or your own
customizations cause the debugger to call extra code, and that extra
code signals an error, then that extra code needs to be fixed, not
Emacs.
> Also concerning is the fact that,
>
> - (string-match "." nil) gives the expected error backtrace.
> - But (string-match-p "." nil) gives the help-function-arglist error.
Sorry, I fail to see the significance of this to the issue at hand.
They are two different functions, and we still don't know which
functions were advised and how.
Perhaps the advice will explain the
difference. Or perhaps we understand the reason for the difference
once we get to the bottom of investigating the problem. Either way,
the efficient method of looking into this problem is to understand
what are those advices and where do they come from.
--
Kaushal Modi