Fix AuTest failure on Linux

Author: masaori335

src/proxy/http/HttpSM.cc

@@ -4688,8 +4688,15 @@ HttpSM::track_connect_fail() const
   // Excludes two cases:
   // - Reused keep-alive connection: there is a known race between ATS reusing and the origin closing it.
   // - Multiplexed origins (HTTP/2): stream-level failure does not indicate a connection failure.
-  if (policy >= 4 && !origin_multiplexed() && server_response_hdr_bytes == 0 && server_txn->is_first_transaction()) {
-    return true;
+  if (policy >= 4) {
+    bool multiplexed = false;
+    auto ssn         = server_txn->get_proxy_ssn();
+    if (ssn != nullptr) {
+      multiplexed = static_cast<PoolableSession *>(ssn)->is_multiplexing();
+    }
+    if (!multiplexed && server_txn->is_first_transaction() && server_response_hdr_bytes == 0) {
+      return true;
+    }
   }
 
   return false;

tests/gold_tests/connect_down_policy/replay/connect_down_policy_4.replay.yaml

@@ -26,19 +26,19 @@ autest:
   description: 'Verify connect down policy 4 - origin closes connection without sending a response'
 
   dns:
-    name: 'dns-dp-4'
+    name: 'dns-policy-4'
     records:
       backend1.example.com: ["127.0.0.1"]
       backend2.example.com: ["127.0.0.1"]
 
   server:
-    name: 'server-dp-4'
+    name: 'server-policy-4'
 
   client:
-    name: 'client-dp-4'
+    name: 'client-policy-4'
 
   ats:
-    name: 'ts-dp-4'
+    name: 'ts-policy-4'
     process_config:
       enable_cache: false
 
@@ -93,6 +93,9 @@ sessions:
     proxy-request:
       expect: absent
 
+    server-response:
+      status: 200
+
     proxy-response:
       status: 500
 
@@ -125,5 +128,8 @@ sessions:
     proxy-request:
       expect: absent
 
+    server-response:
+      status: 200
+
     proxy-response:
       status: 500