Prevents a NPE when there is no subscriber for user events (#8258)

Author: manuel-alvarez-alvarez

dd-java-agent/appsec/src/test/groovy/com/datadog/appsec/user/AppSecEventTrackerSpecification.groovy

@@ -268,6 +268,15 @@ class AppSecEventTrackerSpecification extends DDSpecification {
  thrown(BlockingException)
  }
 
+ void 'should not fail on null callback'() {
+ when:
+ tracker.onUserEvent(UserIdCollectionMode.IDENTIFICATION, 'test-user')
+
+ then:
+ noExceptionThrown()
+ provider.getCallback(EVENTS.user()) >> null
+ }
+
  private static class ActionFlow<T> implements Flow<T> {
 
  private Action action

dd-java-agent/instrumentation/spring-security-5/src/main/java/datadog/trace/instrumentation/springsecurity5/AppSecDeferredContext.java

@@ -1,10 +1,14 @@
 package datadog.trace.instrumentation.springsecurity5;
 
 import java.util.function.Supplier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.security.core.context.SecurityContext;
 
 public class AppSecDeferredContext implements Supplier<SecurityContext> {
 
+ private static final Logger LOGGER = LoggerFactory.getLogger(AppSecDeferredContext.class);
+
  private final Supplier<SecurityContext> delegate;
 
  public AppSecDeferredContext(final Supplier<SecurityContext> delegate) {
@@ -15,7 +19,11 @@ public AppSecDeferredContext(final Supplier<SecurityContext> delegate) {
  public SecurityContext get() {
  SecurityContext context = delegate.get();
  if (context != null) {
- SpringSecurityUserEventDecorator.DECORATE.onUser(context.getAuthentication());
+ try {
+ SpringSecurityUserEventDecorator.DECORATE.onUser(context.getAuthentication());
+ } catch (Throwable e) {
+ LOGGER.debug("Error handling user event", e);
+ }
  }
  return context;
  }

internal-api/src/main/java/datadog/trace/api/appsec/AppSecEventTracker.java

@@ -142,6 +142,9 @@ private <T> void dispatch(
  return;
  }
  final T callback = cbp.getCallback(event);
+ if (callback == null) {
+ return;
+ }
  final Flow<Void> flow = consumer.apply(ctx, callback);
  if (flow == null) {
  return;