`IsProp`( cat, object_or_morphism ) does not save the result compared to `IsProp`( object_or_morphism )

[mohamed-barakat]

[zickgraf]

Note: When compiling code, the side effect of setting IsProp cannot be used anyway. So if there is a situation where setting IsProp is important beyond simple caching and which should be compiled, we have to find a different solution.

[mohamed-barakat]

As just discussed with Fabian: One quick solution would be to augment the method record entry of IsProp with a post-function that sets the value of the property to the computed one.

[mohamed-barakat]

@TKuh: This could be also a quick and simple task.