When editing an existing, correct custom query, the previous result stays on screen, whether the new query version is correct or erroneous.

[mvanbrab]

Example SPARQL query used in the correct custom query:

SELECT ?s ?p ?o WHERE {
  ?s ?p ?o
}

Example erroneous SPARQL query used in the update (mind the ?o2):

SELECT ?s ?p ?o2 WHERE {
  ?s ?p ?o
}

The updated result view shows an error at the bottom indeed, but the previous result table is still visible:

[EmilioTR]

I did not find an immediate cause for this issue. However, I have a solution in sight that will enhance the robustness of the query editor. We should implement a validation check when submitting a new or edited query to prevent submission if the query is faulty.

[mvanbrab]

The SPARQL query validation check is requested in #143.
Let's not use it to avoid the current issue.
We can use the current observation to understand why the displayed result table is out of sync, something that also happens randomly in other circumstances, where we see an old result that subsequently is updated with a new result.

[mvanbrab]

It is even worse than originally reported: when modifying a correct custom query, the result is not updated, even if the updated custom query is correct.

So if e.g. the query is changed from

SELECT ?s ?p ?o WHERE {
  ?s ?p ?o
}

to

SELECT ?s ?o WHERE {
  ?s ?p ?o
}

The result remains unchanged (the p column is not removed in this case).

I'm changing the issue title.