From dc0d311ea746170e7ec1b7355c6ffe419b43e9dc Mon Sep 17 00:00:00 2001
From: Mariia Skripchenko <61115099+marychatte@users.noreply.github.com>
Date: Thu, 4 Apr 2024 08:36:36 +0200
Subject: [PATCH] KTOR-6839 Fix double logging response in CallLogging (#4016)

(cherry picked from commit 3a605a6abd0394d764c0e20eb78b3bd958a9f40f)
---
 .../ktor/server/plugins/callloging/MDCHook.kt |  6 ++++
 .../plugins/callloging/CallLoggingTest.kt     | 29 +++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/src/io/ktor/server/plugins/callloging/MDCHook.kt b/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/src/io/ktor/server/plugins/callloging/MDCHook.kt
index d4edd0ee38..82e48a3695 100644
--- a/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/src/io/ktor/server/plugins/callloging/MDCHook.kt
+++ b/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/src/io/ktor/server/plugins/callloging/MDCHook.kt
@@ -6,6 +6,7 @@ package io.ktor.server.plugins.callloging
 
 import io.ktor.server.application.*
 import io.ktor.server.response.*
+import io.ktor.util.*
 import io.ktor.util.pipeline.*
 
 internal fun MDCHook(phase: PipelinePhase) = object : Hook<suspend (ApplicationCall, suspend () -> Unit) -> Unit> {
@@ -25,8 +26,13 @@ internal fun MDCHook(phase: PipelinePhase) = object : Hook<suspend (ApplicationC
 internal object ResponseSent : Hook<suspend (ApplicationCall) -> Unit> {
     override fun install(pipeline: ApplicationCallPipeline, handler: suspend (ApplicationCall) -> Unit) {
         pipeline.sendPipeline.intercept(ApplicationSendPipeline.Engine) {
+            if (call.attributes.contains(responseSentMarker)) return@intercept
+
+            call.attributes.put(responseSentMarker, Unit)
             proceed()
             handler(call)
         }
     }
 }
+
+private val responseSentMarker = AttributeKey<Unit>("ResponseSentTriggered")
diff --git a/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/test/io/ktor/server/plugins/callloging/CallLoggingTest.kt b/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/test/io/ktor/server/plugins/callloging/CallLoggingTest.kt
index 68eb9eae9f..9067139a6c 100644
--- a/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/test/io/ktor/server/plugins/callloging/CallLoggingTest.kt
+++ b/ktor-server/ktor-server-plugins/ktor-server-call-logging/jvm/test/io/ktor/server/plugins/callloging/CallLoggingTest.kt
@@ -568,6 +568,35 @@ class CallLoggingTest {
         assertContains(messages, "INFO: /without [hardcoded=1]")
     }
 
+    @Test
+    fun `no double logging when with Status Pages`() = testApplication {
+        environment {
+            log = logger
+        }
+        application {
+            install(CallLogging) {
+                format { it.request.uri }
+            }
+            install(StatusPages) {
+                status(HttpStatusCode.BadRequest) { call, _ ->
+                    call.respond("From StatusPages")
+                }
+            }
+        }
+        routing {
+            get {
+                call.respond(HttpStatusCode.BadRequest)
+            }
+        }
+
+        client.get("/").apply {
+            assertEquals(HttpStatusCode.OK, status)
+            assertEquals("From StatusPages", bodyAsText())
+        }
+
+        assertEquals(1, messages.count { it == "INFO: /" })
+    }
+
     private fun green(value: Any): String = colored(value, Ansi.Color.GREEN)
     private fun red(value: Any): String = colored(value, Ansi.Color.RED)
     private fun cyan(value: Any): String = colored(value, Ansi.Color.CYAN)