currentKnownSubject is not set correctly if previous login attempt was failed

[rksk]

Steps to reproduce

1. Configure a service provider with basic authenticator as the first step
2. Add the following script to script based adaptive authentication

   function onLoginRequest(context) {
   executeStep(1, {
       onSuccess: function (context) {
           // Extracting authenticated subject from the first step
           var user = context.currentKnownSubject;
       }
   });
   }

3. First try to login with an invalid credentials pair
4. Try to login with a valid credentials pair
5. Following error is logged and authentication fails

   ERROR {org.wso2.carbon.identity.application.authentication.framework.config.model.graph.JsGraphBuilder} -  Error in executing the javascript for service provider : test, Javascript Fragment : 
   function (context) {
           // Extracting authenticated subject from the first step
           var user = context.currentKnownSubject;
       }
   java.lang.IllegalArgumentException: Wrapped object cannot be null.
   at org.wso2.carbon.identity.application.authentication.framework.config.model.graph.js.AbstractJSObjectWrapper.<init>(AbstractJSObjectWrapper.java:32)
   at org.wso2.carbon.identity.application.authentication.framework.config.model.graph.js.JsAuthenticatedUser.<init>(JsAuthenticatedUser.java:78)
   at org.wso2.carbon.identity.application.authentication.framework.config.model.graph.js.JsAuthenticatedUser.<init>(JsAuthenticatedUser.java:65)
   at org.wso2.carbon.identity.application.authentication.framework.config.model.graph.js.JsAuthenticationContext.getMember(JsAuthenticationContext.java:79)
   at jdk.nashorn.internal.scripts.Script$Recompilation$29$19A$\^eval\_.L:1(<eval>:3)
   at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:659)
   at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:494)
   at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
   at jdk.nashorn.api.scripting.ScriptObjectMirror.call(ScriptObjectMirror.java:117)
   at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.lambda$executeFunction$1(GraphBasedSequenceHandler.java:606)
   at org.wso2.carbon.identity.application.authentication.framework.config.model.graph.JsGraphBuilder$JsBasedEvaluator.evaluate(JsGraphBuilder.java:840)
   at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.executeFunction(GraphBasedSequenceHandler.java:606)
   at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.handleDecisionPoint(GraphBasedSequenceHandler.java:571)
   at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.handleNode(GraphBasedSequenceHandler.java:168)
   at org.wso2.carbon.identity.application.authentication.framework.handler.sequence.impl.GraphBasedSequenceHandler.handle(GraphBasedSequenceHandler.java:125)
   at org.wso2.carbon.identity.application.authentication.framework.handler.request.impl.DefaultAuthenticationRequestHandler.handle(DefaultAuthenticationRequestHandler.java:139)
   at org.wso2.carbon.identity.application.authentication.framework.handler.request.impl.DefaultRequestCoordinator.handle(DefaultRequestCoordinator.java:244)
   at org.wso2.carbon.identity.application.authentication.framework.servlet.CommonAuthenticationServlet.doPost(CommonAuthenticationServlet.java:53)

Workaround To avoid this issue, we can get the subject from the previous step as below. var user = context.steps[1].subject;

[pamodaaw]

This issue occurs for the same reason as https://github.com/wso2/product-is/issues/5779. It has been fixed with https://github.com/wso2/carbon-identity-framework/pull/2264