From e95ce2c2fc41cb454dbcbd32ddec67f148f2285e Mon Sep 17 00:00:00 2001
From: Oleg Kalnichevski <olegk@apache.org>
Date: Sat, 12 Oct 2024 15:22:39 +0200
Subject: [PATCH] Bug fix: allow `Host` headers in HTTP/2 request messages

---
 .../core5/http2/protocol/H2RequestConformance.java |  1 -
 .../core5/http2/protocol/TestH2Interceptors.java   |  4 ++--
 .../compatibility/http2/ApacheHttpDCompatIT.java   | 14 --------------
 3 files changed, 2 insertions(+), 17 deletions(-)

diff --git a/httpcore5-h2/src/main/java/org/apache/hc/core5/http2/protocol/H2RequestConformance.java b/httpcore5-h2/src/main/java/org/apache/hc/core5/http2/protocol/H2RequestConformance.java
index a2d010b14..ef528fbc2 100644
--- a/httpcore5-h2/src/main/java/org/apache/hc/core5/http2/protocol/H2RequestConformance.java
+++ b/httpcore5-h2/src/main/java/org/apache/hc/core5/http2/protocol/H2RequestConformance.java
@@ -67,7 +67,6 @@ public H2RequestConformance() {
                 HttpHeaders.KEEP_ALIVE,
                 HttpHeaders.PROXY_CONNECTION,
                 HttpHeaders.TRANSFER_ENCODING,
-                HttpHeaders.HOST,
                 HttpHeaders.UPGRADE,
                 HttpHeaders.TE);
     }
diff --git a/httpcore5-h2/src/test/java/org/apache/hc/core5/http2/protocol/TestH2Interceptors.java b/httpcore5-h2/src/test/java/org/apache/hc/core5/http2/protocol/TestH2Interceptors.java
index ef2e84aaa..38410c787 100644
--- a/httpcore5-h2/src/test/java/org/apache/hc/core5/http2/protocol/TestH2Interceptors.java
+++ b/httpcore5-h2/src/test/java/org/apache/hc/core5/http2/protocol/TestH2Interceptors.java
@@ -194,8 +194,8 @@ void testH2RequestConformanceHostHeader() {
         request.addHeader("Host", "host");
 
         final H2RequestConformance interceptor = new H2RequestConformance();
-        Assertions.assertThrows(HttpException.class, () -> interceptor.process(request, null, context),
-                "Header 'Host: host' is illegal for HTTP/2 messages");
+        Assertions.assertDoesNotThrow(() -> interceptor.process(request, null, context),
+                "Header 'Host: host' is permissible for HTTP/2 messages");
     }
 
     @Test
diff --git a/httpcore5-testing/src/test/java/org/apache/hc/core5/testing/compatibility/http2/ApacheHttpDCompatIT.java b/httpcore5-testing/src/test/java/org/apache/hc/core5/testing/compatibility/http2/ApacheHttpDCompatIT.java
index 55ce9cea2..0277dba0a 100644
--- a/httpcore5-testing/src/test/java/org/apache/hc/core5/testing/compatibility/http2/ApacheHttpDCompatIT.java
+++ b/httpcore5-testing/src/test/java/org/apache/hc/core5/testing/compatibility/http2/ApacheHttpDCompatIT.java
@@ -27,11 +27,8 @@
 
 package org.apache.hc.core5.testing.compatibility.http2;
 
-import org.apache.hc.core5.http.HttpHeaders;
 import org.apache.hc.core5.http.HttpHost;
-import org.apache.hc.core5.http2.impl.H2Processors;
 import org.apache.hc.core5.http2.impl.nio.bootstrap.H2RequesterBootstrap;
-import org.apache.hc.core5.http2.protocol.H2RequestConformance;
 import org.apache.hc.core5.testing.compatibility.ContainerImages;
 import org.junit.jupiter.api.AfterAll;
 import org.testcontainers.containers.GenericContainer;
@@ -46,17 +43,6 @@ class ApacheHttpDCompatIT extends AbstractHttp2CompatIT {
 
     @Override
     void configure(final H2RequesterBootstrap bootstrap) {
-        bootstrap.setHttpProcessor(H2Processors.customClient(null)
-                .addFirst(new H2RequestConformance(
-                        HttpHeaders.CONNECTION,
-                        HttpHeaders.KEEP_ALIVE,
-                        HttpHeaders.PROXY_CONNECTION,
-                        HttpHeaders.TRANSFER_ENCODING,
-// For some reason Apache HTTPD includes Host header in HTTP/2 promise messages
-// though it should not
-//                        HttpHeaders.HOST,
-                        HttpHeaders.UPGRADE))
-                .build());
     }
 
     HttpHost targetHost() {