If the limits don't make sense use linear interpolation in Modelica.Fluid.Utilities.regfun3

[HansOlsson]

See #4128 (comment)

I'm not saying that it fully corrects the issues with regfun3 - but at least it is a clear improvement that avoids the common failures.
Closes #3758
(Yes, I re-ran that example - the jump is gone).

Note I'm not saying that it completes the investigation of regfun3 and thus I don't see it as closing #4128
It could be that after a proper investigation and correction that regfun3 will never generate out-of-bounds values for those variables.

[casella]

Definitely an improvement, if not the definitive one. If it solves the original issue, go for it.

[casella]

@HansOlsson this should resolve #3758. Did you test that when you made the commit? If so, we can close this ticket as well as #3758.

[HansOlsson]

@HansOlsson this should resolve #3758. Did you test that when you made the commit? If so, we can close this ticket as well as #3758.

(I assume you mean close by merging, right?
Yes, I tested that it resolved the jump in #3758

However, I think that someone should still investigate regfun3 in general (at some point in time).
That's why I proposed that this closes #3758 but leaving #4128 open.