From 72302396092053fa648ab7d0300843634f66c73d Mon Sep 17 00:00:00 2001
From: Pierre Adam <adam.pierre.dany@gmail.com>
Date: Wed, 20 Mar 2024 19:45:53 +0100
Subject: [PATCH] Fixes #39586. Properly use headers from RestMulti when the
 datasource is empty.

Signed-off-by: Pierre Adam <adam.pierre.dany@gmail.com>
---
 .../deployment/test/streams/StreamResource.java     | 13 +++++++++++++
 .../deployment/test/streams/StreamTestCase.java     |  8 ++++++++
 .../server/handlers/PublisherResponseHandler.java   |  2 +-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamResource.java b/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamResource.java
index 01895dfbe7026..97292e3956c68 100644
--- a/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamResource.java
+++ b/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamResource.java
@@ -199,6 +199,19 @@ public Multi<Message> multiNdJson2() {
                 Wrapper::getStatus);
     }
 
+    @Path("restmulti/empty")
+    @GET
+    @Produces(RestMediaType.APPLICATION_JSON)
+    public Multi<Message> restMultiEmptyJson() {
+        return RestMulti.fromUniResponse(
+                Uni.createFrom().item(
+                        () -> new Wrapper(Multi.createFrom().empty(),
+                                new AbstractMap.SimpleEntry<>("foo", "bar"), 222)),
+                Wrapper::getData,
+                Wrapper::getHeaders,
+                Wrapper::getStatus);
+    }
+
     @Path("stream-json/multi")
     @GET
     @Produces(RestMediaType.APPLICATION_STREAM_JSON)
diff --git a/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamTestCase.java b/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamTestCase.java
index 915ad45721cf7..737390d382051 100644
--- a/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamTestCase.java
+++ b/extensions/resteasy-reactive/rest-jackson/deployment/src/test/java/io/quarkus/resteasy/reactive/jackson/deployment/test/streams/StreamTestCase.java
@@ -174,6 +174,14 @@ public void testNdJsonMultiFromMulti2() {
                 .header("foo", "bar");
     }
 
+    @Test
+    public void testRestMultiEmptyJson() {
+        when().get(uri.toString() + "streams/restmulti/empty")
+                .then().statusCode(222)
+                .body(is("[]"))
+                .header("foo", "bar");
+    }
+
     @Test
     public void testStreamJsonMultiFromMulti() {
         when().get(uri.toString() + "streams/stream-json/multi")
diff --git a/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/PublisherResponseHandler.java b/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/PublisherResponseHandler.java
index c1af678260549..20110476a41f8 100644
--- a/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/PublisherResponseHandler.java
+++ b/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/handlers/PublisherResponseHandler.java
@@ -151,7 +151,7 @@ private List<StreamingResponseCustomizer> determineCustomizers(boolean isFirst)
         @Override
         public void onComplete() {
             if (!hadItem) {
-                StreamingUtil.setHeaders(requestContext, requestContext.serverResponse(), staticCustomizers);
+                StreamingUtil.setHeaders(requestContext, requestContext.serverResponse(), this.determineCustomizers(true));
             }
             if (json) {
                 String postfix = onCompleteText();