fix #2772 Subrouter failure handler is ignored

vertx-web/src/main/java/io/vertx/ext/web/impl/RoutingContextImplBase.java

@@ -163,6 +163,19 @@ boolean iterateNext() {
           currentRoute.handleFailure(this);
           return true;
         }
+
+        RouterImpl subRouter = (RouterImpl) currentRoute.getSubRouter();
+        if (subRouter != null) {
+          int statusCode = statusCode();
+          if (statusCode == -1) {
+            statusCode = failed ? 500 : matchFailure;
+          }
+          Handler<RoutingContext> errorHandler = subRouter.getErrorHandlerByStatusCode(statusCode);
+          if (errorHandler != null) {
+            errorHandler.handle(this);
+            return true;
+          }
+        }
       } catch (Throwable t) {
         handleInHandlerRuntimeFailure(currentRoute.getRouter(), failed, t);
         return true;

vertx-web/src/test/java/io/vertx/ext/web/tests/SubRouterTest.java

@@ -23,6 +23,7 @@
 import io.vertx.ext.web.RoutingContext;
 import org.junit.Test;
 
+import java.util.concurrent.TimeoutException;
 import java.util.function.Consumer;
 
 /**
@@ -743,4 +744,48 @@ public void testHierarchicalWithParamsSimpleWithDummy() throws Exception {
 
     testRequest(HttpMethod.GET, "/rest/product/123/bar", 200, "OK");
   }
+
+  @Test
+  public void testSetExceptionHandler() throws Exception {
+    Router restRouter = Router.router(vertx);
+    Router productRouter = Router.router(vertx);
+    Router instanceRouter = Router.router(vertx);
+
+    router.route("/rest*").subRouter(restRouter);
+    restRouter.route("/product*").subRouter(productRouter);
+    productRouter.route("/:id*").subRouter(instanceRouter);
+    instanceRouter.get("/:foo").handler(ctx -> {
+      if ("ex".equals(ctx.pathParam("foo"))) {
+        throw new RuntimeException("ouch!");
+      }
+      ctx.response().end();
+    });
+
+    requestGet("/rest/product/123/ex", (response, buffer) -> {
+      assertEquals(500, response.statusCode());
+      assertEquals("Internal Server Error", buffer.toString());
+    });
+
+    assertRouterErrorHandlers("root", router, 500, "/rest/product/123/ex");
+    assertRouterErrorHandlers("root", router, 404, "/rest/product/123/foo/404");
+
+    assertRouterErrorHandlers("rest", restRouter, 500, "/rest/product/123/ex");
+    assertRouterErrorHandlers("rest", restRouter, 404, "/rest/product/123/foo/404");
+
+    assertRouterErrorHandlers("product", productRouter, 500, "/rest/product/123/ex");
+    assertRouterErrorHandlers("product", productRouter, 404, "/rest/product/123/foo/404");
+
+    assertRouterErrorHandlers("instance", instanceRouter, 500, "/rest/product/123/ex");
+    assertRouterErrorHandlers("instance", instanceRouter, 404, "/rest/product/123/foo/404");
+  }
+
+  private void assertRouterErrorHandlers(String name, Router router, int statusCode, String path) throws TimeoutException {
+    String handlerKey = name + "." + statusCode + ".errorHandler";
+    router.errorHandler(statusCode, ctx -> ctx.response().setStatusCode(statusCode).end(handlerKey));
+
+    requestGet(path, (response, buffer) -> {
+      assertEquals(statusCode, response.statusCode());
+      assertEquals(handlerKey, buffer.toString());
+    });
+  }
 }

vertx-web/src/test/java/io/vertx/ext/web/tests/WebTestBase.java

@@ -17,6 +17,7 @@
 package io.vertx.ext.web.tests;
 
 import io.netty.handler.codec.http.HttpResponseStatus;
+import io.vertx.core.Future;
 import io.vertx.core.buffer.Buffer;
 import io.vertx.core.http.*;
 import io.vertx.ext.web.Router;
@@ -36,6 +37,9 @@
 import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 
 /**
@@ -317,4 +321,14 @@ public static void cleanupFileUploadDir() throws IOException {
     }
   }
 
+  long timeout = 200;
+  TimeUnit timeoutUnit = TimeUnit.MILLISECONDS;
+
+  public void requestGet(String path, BiConsumer<HttpClientResponse, Buffer> assertAction) throws TimeoutException {
+    RequestOptions options = new RequestOptions().setHost("localhost").setPort(server.actualPort()).setURI(path);
+    client.request(options).compose(HttpClientRequest::send).compose(resp -> resp.body().compose(buffer -> {
+      assertAction.accept(resp, buffer);
+      return Future.succeededFuture();
+    })).await(timeout, timeoutUnit);
+  }
 }