transformer fails to transform iModels with view definitions that have null category selectors

[MichaelBelousov]

Transformer fails to transform iModels with view definitions that have null category selectors.
Need to come up with a test case to demonstrate this crash and then a fix.

also need to test null model selectors

[nick4598]

@MichaelBelousov is this #27 related?

[MichaelBelousov]

@MichaelBelousov is this #27 related?

I don't believe so, this allegedly throws, that is a data transfer failure where the transformation succeeds.

[MichaelBelousov]

I recently was looking at the code... are null category selectors even valid? The domain handler inserts a default one if you try to make a null one... so it is an unexpected delete at the core level... this may cause issues further in the stack...

@mindaugasdirg from what connectors does the iModel exhibiting this come from?