Allow empty @BeanParam class with non-empty super class

independent-projects/resteasy-reactive/server/processor/src/main/java/org/jboss/resteasy/reactive/server/processor/ServerEndpointIndexer.java

@@ -167,7 +167,7 @@ protected boolean handleBeanParam(ClassInfo actualEndpointInfo, Type paramType,
         InjectableBean injectableBean = scanInjectableBean(beanParamClassInfo,
                 actualEndpointInfo,
                 existingConverters, additionalReaders, injectableBeans, hasRuntimeConverters);
-        if (injectableBean.getFieldExtractorsCount() == 0) {
+        if ((injectableBean.getFieldExtractorsCount() == 0) && !injectableBean.isInjectionRequired()) {
             throw new DeploymentException(String.format("No annotations found on fields at '%s'. "
                     + "Annotations like `@QueryParam` should be used in fields, not in methods.",
                     beanParamClassInfo.name()));
@@ -288,7 +288,7 @@ protected InjectableBean scanInjectableBean(ClassInfo currentClassInfo, ClassInf
 
         currentInjectableBean.setFieldExtractorsCount(fieldExtractors.size());
 
-        if (!fieldExtractors.isEmpty() && fieldInjectionHandler != null) {
+        if ((fieldInjectionHandler != null) && (!fieldExtractors.isEmpty() || superTypeIsInjectable)) {
             fieldInjectionHandler.handleFieldInjection(currentTypeName, fieldExtractors, superTypeIsInjectable);
         }
         currentInjectableBean.setInjectionRequired(!fieldExtractors.isEmpty() || superTypeIsInjectable);

independent-projects/resteasy-reactive/server/vertx/src/test/java/org/jboss/resteasy/reactive/server/vertx/test/simple/BeanParamEmptySubclassTest.java

@@ -0,0 +1,58 @@
+package org.jboss.resteasy.reactive.server.vertx.test.simple;
+
+import io.restassured.RestAssured;
+import javax.ws.rs.BeanParam;
+import javax.ws.rs.FormParam;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.MediaType;
+import org.hamcrest.Matchers;
+import org.jboss.resteasy.reactive.server.vertx.test.framework.ResteasyReactiveUnitTest;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+public class BeanParamEmptySubclassTest {
+
+    @RegisterExtension
+    static ResteasyReactiveUnitTest test = new ResteasyReactiveUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addClasses(TestResource.class, BaseParams.class, Params.class));
+
+    @Test
+    public void test() {
+        RestAssured.given().formParam("param1", "foo").post("/bean?param2=bar")
+                .then().statusCode(200).body(Matchers.equalTo("foo/bar"));
+    }
+
+    @Path("bean")
+    public static class TestResource {
+
+        @POST
+        @Produces(MediaType.TEXT_PLAIN)
+        public String hello(final @BeanParam BaseParams params) {
+            return params.getParam1() + "/" + params.getParam2();
+        }
+    }
+
+    public static class BaseParams {
+        @FormParam("param1")
+        private String param1;
+
+        @QueryParam("param2")
+        private String param2;
+
+        public String getParam1() {
+            return param1;
+        }
+
+        public String getParam2() {
+            return param2;
+        }
+    }
+
+    public static class Params extends BaseParams {
+
+    }
+}