Dynamo: Bug, Dynamo 0.82: Revit nodes fail if the first item in the input list is a null or an empty list.

[dimven]

I would classify this as a major annoyance. I first noticed it happening in 0.81. So far the following nodes are affected:

Element.GetParameterValueByName
Element.SetParameterByName
Element.Name

there might be more.

There is no problem if the null value or empty list is not at head of the list:

However, if it is, the whole list fails to process:

We can remedy this with a list.map but this is not an optimal approach:

[monikaprabhu]

@dimven - what is the error /warning shown on these nodes ?

[dimven]

Hi @monikaprabhu , the error message is:
_Warning: Internal error, please report: Dereferencing a non-pointer. (3f47aacd)_

[sharadkjaiswal]

@ke-yu, can it be related to Type inferencing issue?

[monikaprabhu]

@dimven - we have an open issue related to this - which is tracked at - MAGN-6873.Im afraid its the same issue as -https://github.com/DynamoDS/Dynamo/issues/4116. I'll leave a messege to development team to see if we can increase the priority of fixing this. Thanks for reporting it.

[monikaprabhu]

@dimven - you can use List.Clean to remove the null/EmptyList from the input to Element.SetparameterName.

[dimven]

@monikaprabhu Thanks for the info.
I'd personally prefer to keep the null value there, so that the structure of the list is preserved.

[ikeough]

Internal issue has been closed.

[ke-yu]

https://github.com/DynamoDS/Dynamo/pull/7178

[dimven]

was #7178 merged in 1.21? This is still an issue active issue:

[aparajit-pratap]

Fixed in #9559 and https://github.com/DynamoDS/Dynamo/pull/9578