Fix dev-mode CL issue with multipart form handling

Fixes: quarkusio#16794

extensions/resteasy-reactive/quarkus-resteasy-reactive/deployment/src/test/java/io/quarkus/resteasy/reactive/server/test/multipart/MultipartFormInputDevModeTest.java

@@ -0,0 +1,79 @@
+package io.quarkus.resteasy.reactive.server.test.multipart;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+
+import java.io.File;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.resteasy.reactive.server.test.multipart.other.OtherPackageFormDataBase;
+import io.quarkus.test.QuarkusDevModeTest;
+import io.restassured.RestAssured;
+
+public class MultipartFormInputDevModeTest {
+
+    @RegisterExtension
+    static QuarkusDevModeTest TEST = new QuarkusDevModeTest()
+            .setArchiveProducer(new Supplier<JavaArchive>() {
+                @Override
+                public JavaArchive get() {
+                    return ShrinkWrap.create(JavaArchive.class)
+                            .addClasses(FormDataBase.class, OtherPackageFormDataBase.class, FormData.class, Status.class,
+                                    OtherFormData.class, OtherFormDataBase.class, MultipartResource.class);
+                }
+
+            });
+
+    private final File HTML_FILE = new File("./src/test/resources/test.html");
+    private final File XML_FILE = new File("./src/test/resources/test.html");
+    private final File TXT_FILE = new File("./src/test/resources/lorem.txt");
+
+    @Test
+    public void test() {
+        doTest("simple");
+        doTest("simple");
+
+        TEST.modifySourceFile(MultipartResource.class.getSimpleName() + ".java", new Function<String, String>() {
+            @Override
+            public String apply(String s) {
+                return s.replace("/simple", "/simple2");
+            }
+        });
+
+        doTest("simple2");
+        doTest("simple2");
+
+        TEST.modifySourceFile(MultipartResource.class.getSimpleName() + ".java", new Function<String, String>() {
+            @Override
+            public String apply(String s) {
+                return s.replace("/simple2", "/simple");
+            }
+        });
+
+        doTest("simple");
+        doTest("simple");
+    }
+
+    private void doTest(String path) {
+        RestAssured.given()
+                .multiPart("name", "Alice")
+                .multiPart("active", "true")
+                .multiPart("num", "25")
+                .multiPart("status", "WORKING")
+                .multiPart("htmlFile", HTML_FILE, "text/html")
+                .multiPart("xmlFile", XML_FILE, "text/xml")
+                .multiPart("txtFile", TXT_FILE, "text/plain")
+                .accept("text/plain")
+                .when()
+                .post("/multipart/" + path + "/2")
+                .then()
+                .statusCode(200)
+                .body(equalTo("Alice - true - 50 - WORKING - text/html - true - true"));
+    }
+
+}

extensions/resteasy-reactive/quarkus-resteasy-reactive/runtime/src/main/java/io/quarkus/resteasy/reactive/server/runtime/MultipartFormHandler.java

@@ -47,12 +47,15 @@ public class MultipartFormHandler implements RuntimeConfigurableServerRestHandle
     private volatile String uploadsDirectory;
     private volatile boolean deleteUploadedFilesOnEnd;
     private volatile Optional<Long> maxBodySize;
+    private volatile ClassLoader tccl;
 
     @Override
     public void configure(RuntimeConfiguration configuration) {
         uploadsDirectory = configuration.body().uploadsDirectory();
         deleteUploadedFilesOnEnd = configuration.body().deleteUploadedFilesOnEnd();
         maxBodySize = configuration.limits().maxBodySize();
+        // capture the proper TCCL in order to avoid losing it to Vert.x in dev-mode
+        tccl = Thread.currentThread().getContextClassLoader();
 
         try {
             Files.createDirectories(Paths.get(uploadsDirectory));
@@ -80,7 +83,7 @@ public void handle(ResteasyReactiveRequestContext context) throws Exception {
             httpServerRequest.setExpectMultipart(true);
             httpServerRequest.pause();
             context.suspend();
-            MultipartFormVertxHandler handler = new MultipartFormVertxHandler(context, uploadsDirectory,
+            MultipartFormVertxHandler handler = new MultipartFormVertxHandler(context, tccl, uploadsDirectory,
                     deleteUploadedFilesOnEnd, maxBodySize);
             httpServerRequest.handler(handler);
             httpServerRequest.endHandler(new Handler<Void>() {
@@ -96,6 +99,7 @@ public void handle(Void event) {
     private static class MultipartFormVertxHandler implements Handler<Buffer> {
         private final ResteasyReactiveRequestContext rrContext;
         private final RoutingContext context;
+        private final ClassLoader tccl;
 
         private final String uploadsDirectory;
         private final boolean deleteUploadedFilesOnEnd;
@@ -107,10 +111,11 @@ private static class MultipartFormVertxHandler implements Handler<Buffer> {
         boolean ended;
         long uploadSize = 0L;
 
-        public MultipartFormVertxHandler(ResteasyReactiveRequestContext rrContext, String uploadsDirectory,
+        public MultipartFormVertxHandler(ResteasyReactiveRequestContext rrContext, ClassLoader tccl, String uploadsDirectory,
                 boolean deleteUploadedFilesOnEnd, Optional<Long> maxBodySize) {
             this.rrContext = rrContext;
             this.context = rrContext.serverRequest().unwrap(RoutingContext.class);
+            this.tccl = tccl;
             this.uploadsDirectory = uploadsDirectory;
             this.deleteUploadedFilesOnEnd = deleteUploadedFilesOnEnd;
             this.maxBodySize = maxBodySize;
@@ -134,6 +139,7 @@ public void handle(HttpServerFileUpload upload) {
                         long size = uploadSize + upload.size();
                         if (size > MultipartFormVertxHandler.this.maxBodySize.get()) {
                             failed = true;
+                            restoreProperTCCL();
                             rrContext.resume(new WebApplicationException(Response.Status.REQUEST_ENTITY_TOO_LARGE));
                             return;
                         }
@@ -191,10 +197,15 @@ public void handle(Void v) {
                         MultipartFormVertxHandler.this.deleteFileUploads();
                     }
                 });
+                restoreProperTCCL();
                 rrContext.resume(new WebApplicationException(Response.Status.REQUEST_ENTITY_TOO_LARGE));
             }
         }
 
+        private void restoreProperTCCL() {
+            Thread.currentThread().setContextClassLoader(tccl);
+        }
+
         void uploadEnded() {
             int count = uploadCount.decrementAndGet();
             // only if parsing is done and count is 0 then all files have been processed
@@ -222,6 +233,7 @@ void doEnd() {
                 context.addBodyEndHandler(x -> deleteFileUploads());
             }
             rrContext.setInputStream(NO_BYTES_INPUT_STREAM);
+            restoreProperTCCL();
             rrContext.resume();
         }