IllegalArgumentException when using BIND or VALUES with nonexisting resource about hdt-java HOT 3 CLOSED

This also happens with literals, e.g.

$ hdtsparql.sh example.hdt 'SELECT * { VALUES ?o { "Example2" }  ?s ?p ?o }'

gives the same exception but with ?o instead of ?s in the error message.

from hdt-java.

HDTSolverLib.java line 201 comment says: // Even put "does not exist" if it is null.
This suggests to me that being able to store a null value is expected.

But actually BindingHDTId.java line 78 checks for a null value and throws an exception.

Possible ways to fix:

1. Change BindingHDTId to allow a null value. Possibly dangerous, since it may cause breakage elsewhere.
2. Check for a null return value from the getID call and shortcut the loop with continue, as is done a few lines above in HDTSolverLib.

I'm unfamiliar with the codebase so I'm not sure about the consequences of these two options, but I can try to do a PR if it's useful. Hints welcome.

from hdt-java.

I tested both approaches (1 and 2 in the previous comment) but they both give invalid results - the queries should return nothing for the example queries and data in the original issue report, but instead they return a binding http://example.org/2,http://schema.org/name,Example.

from hdt-java.