[Python] Query help: False negatives with kwargs #21887

/**
 * @kind path-problem
 * @id broken-python-kwargs
 */

import python

import semmle.python.ApiGraphs
import semmle.python.Concepts
import semmle.python.dataflow.new.TaintTracking

module KwArgsFlow implements DataFlow::ConfigSig {
    predicate isSource(DataFlow::Node node) {
        exists(Call call, Name name | 
            // call is to source
            call.getFunc() = name and name.getId() = "source" 
            // node is the returned value
            and call = node.asExpr()
        )
    }

    predicate isSink(DataFlow::Node node) {
        exists(Call call, Name name |
            // call is to a sink
            call.getFunc() = name and name.getId() in ["sink" ,"sink2"]
            // node is an arg or kwarg
            and (
                call.getAnArg() = node.asExpr()
                or call.getKwargs() = node.asExpr()
            )
        )
    }
}

module Flow = TaintTracking::Global<KwArgsFlow>;
import Flow::PathGraph

from Flow::PathNode input, Flow::PathNode output
where Flow::flowPath(input,output)
select output.getNode(), input, output, "This does not work"