bug#49534: [External] : Re: bug#49534: 26.3; Isearch should support using filter predicates with empty search hits

[Drew Adams]

> > Your code (in master) removes that boundary test
> > altogether (no `bobp' or `eobp' test).  Why is
> > that the right thing?  Is it because the match
> > should be allowed to match up to `bobp' or `eobp'?
> > If so, why was that test in isearch.el in the
> > first place?
> 
> If you think that you found a problem, please provide
> a test that exposes it.

I'm asking why you removed that boundary test.
And peripherally, why it was there to begin with?

> > Actually, you do still test for reaching the
> > boundary, but only for an empty match and after
> > filter failure.  Why is that?
> 
> Please provide a test case if you think there is a problem.

I'm asking why you test for reaching the boundary,
and only for an empty match and after a filter
failure.

> > And why do you not need to back up a char after
> > the loop, if the match was empty the last time
> > around and the next time it fails?  It'll have
> > advanced a char; should it stay there instead
> > of backing up?  (Dunno, but I supposed not.)
> 
> Please provide more tests that confirm your doubts.

I'm asking why you don't need to back up a char
after having advanced a char in that case.