bug#11218: with-demoted-errors use of condition-case-unless-debug; ert

[Stefan Monnier]

>>>> If I want to debug a condition-case, I'll set debug-on-signal non-nil.
>> That's not an ert bug. :)
> To expand: why does with-demoted-errors use a different form of
> condition-case, and hence treat debugging differently, to the
> pre-existing ignore-errors? The former doesn't let you have control; the
> latter does.

debug-on-signal is inconvenient because it triggers in many cases where
it shouldn't (because the error is actually normal and handled
properly).

`with-demoted-errors' doesn't actually *handle* the error, it just
demotes it so as not to annoy the user.  So I find it makes sense to get
into the debugger when an error is demoted and the user has asked to
enter debugger on error.


        Stefan