Support media type suffixes in reactive rest client

Fixes: #21957
(cherry picked from commit ee400a7)

extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/MediaTypeSuffixTest.java

@@ -0,0 +1,69 @@
+package io.quarkus.rest.client.reactive;
+
+import static io.restassured.RestAssured.when;
+import static org.hamcrest.Matchers.is;
+
+import java.util.Map;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+
+import org.eclipse.microprofile.rest.client.inject.RegisterRestClient;
+import org.eclipse.microprofile.rest.client.inject.RestClient;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+
+public class MediaTypeSuffixTest {
+
+    private static final String CUSTOM_JSON_MEDIA_TYPE = "application/vnd.search.v1+json";
+
+    @RegisterExtension
+    static final QuarkusUnitTest TEST = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addClasses(HelloResource.class, Client.class))
+            .withConfigurationResource("media-type-suffix-application.properties");
+
+    @Test
+    public void test() {
+        when()
+                .get("/hello")
+                .then()
+                .statusCode(200)
+                .body("foo", is("bar"));
+    }
+
+    @RegisterRestClient(configKey = "test")
+    @Path("/hello")
+    public interface Client {
+
+        @GET
+        @Path("/custom")
+        @Produces(CUSTOM_JSON_MEDIA_TYPE)
+        Map<String, Object> test();
+    }
+
+    @Path("/hello")
+    public static class HelloResource {
+
+        private final Client client;
+
+        public HelloResource(@RestClient Client client) {
+            this.client = client;
+        }
+
+        @GET
+        @Path("/custom")
+        @Produces(CUSTOM_JSON_MEDIA_TYPE)
+        public Map<String, Object> hello() {
+            return Map.of("foo", "bar");
+        }
+
+        @GET
+        public Map<String, Object> test() {
+            return client.test();
+        }
+    }
+}

extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/resources/media-type-suffix-application.properties

@@ -0,0 +1 @@
+quarkus.rest-client.test.url=http://localhost:${quarkus.http.test-port:8081}

independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientReaderInterceptorContextImpl.java

@@ -17,6 +17,7 @@
 import org.jboss.resteasy.reactive.common.core.Serialisers;
 import org.jboss.resteasy.reactive.common.jaxrs.ConfigurationImpl;
 import org.jboss.resteasy.reactive.common.util.CaseInsensitiveMap;
+import org.jboss.resteasy.reactive.common.util.MediaTypeHelper;
 
 public class ClientReaderInterceptorContextImpl extends AbstractClientInterceptorContextImpl
         implements ReaderInterceptorContext {
@@ -34,7 +35,7 @@ public ClientReaderInterceptorContextImpl(Annotation[] annotations, Class<?> ent
             Map<String, Object> properties, MultivaluedMap<String, String> headers,
             ConfigurationImpl configuration, Serialisers serialisers, InputStream inputStream,
             ReaderInterceptor[] interceptors) {
-        super(annotations, entityClass, entityType, mediaType, properties);
+        super(annotations, entityClass, entityType, MediaTypeHelper.withSuffixAsSubtype(mediaType), properties);
         this.configuration = configuration;
         this.serialisers = serialisers;
         this.inputStream = inputStream;

independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/util/MediaTypeHelper.java

@@ -272,6 +272,9 @@ public static boolean isUnsupportedWildcardSubtype(MediaType mediaType) {
      * that uses the suffix as the subtype
      */
     public static MediaType withSuffixAsSubtype(MediaType mediaType) {
+        if (mediaType == null) {
+            return null;
+        }
         int plusIndex = mediaType.getSubtype().indexOf('+');
         if ((plusIndex > -1) && (plusIndex < mediaType.getSubtype().length() - 1)) {
             mediaType = new MediaType(mediaType.getType(),