Fix KTOR-7665 Jackson should respond with 500 when Jackson converter fails with exception

ktor-server/ktor-server-core/common/src/io/ktor/server/engine/BaseApplicationResponse.kt

@@ -10,7 +10,6 @@ import io.ktor.http.content.*
 import io.ktor.server.application.*
 import io.ktor.server.engine.internal.*
 import io.ktor.server.http.*
-import io.ktor.server.plugins.*
 import io.ktor.server.response.*
 import io.ktor.util.*
 import io.ktor.util.cio.*
@@ -128,10 +127,20 @@ public abstract class BaseApplicationResponse(
 
             // WriteChannelContent is more efficient than ReadChannelContent
             is OutgoingContent.WriteChannelContent -> {
+                val ch = ByteChannel()
+                try {
+                    // need to be in external function to keep tail suspend call
+                    respondWriteChannelContent(ch, content)
+                } catch (cause: Throwable) {
+                    status(HttpStatusCode.InternalServerError)
+                    throw cause
+                }
+
                 // First set headers
                 commitHeaders(content)
-                // need to be in external function to keep tail suspend call
-                respondWriteChannelContent(content)
+                responseChannel().use {
+                    ch.copyTo(this)
+                }
             }
 
             // Pipe is the least efficient
@@ -168,9 +177,9 @@ public abstract class BaseApplicationResponse(
     /**
      * Process response [content] using [OutgoingContent.WriteChannelContent.writeTo].
      */
-    protected open suspend fun respondWriteChannelContent(content: OutgoingContent.WriteChannelContent) {
+    protected open suspend fun respondWriteChannelContent(ch: ByteWriteChannel, content: OutgoingContent.WriteChannelContent) {
         // Retrieve response channel, that might send out headers, so it should go after commitHeaders
-        responseChannel().use {
+        ch.use {
             // Call user code to send data
 //            val before = totalBytesWritten
             try {
@@ -179,6 +188,11 @@ public abstract class BaseApplicationResponse(
                 }
             } catch (closed: ClosedWriteChannelException) {
                 throw ChannelWriteException(exception = closed)
+            } catch (cause: Exception) {
+                status(HttpStatusCode.InternalServerError)
+                println("EXCEPTION")
+                throw cause
+
             }
 
             // TODO currently we can't ensure length like that

ktor-shared/ktor-serialization/ktor-serialization-jackson/jvm/test/ServerJacksonBlockingTest.kt

@@ -7,17 +7,21 @@ import io.ktor.client.request.*
 import io.ktor.http.*
 import io.ktor.serialization.jackson.*
 import io.ktor.server.application.*
+import io.ktor.server.config.*
 import io.ktor.server.plugins.contentnegotiation.*
 import io.ktor.server.request.*
 import io.ktor.server.response.*
 import io.ktor.server.routing.*
 import io.ktor.server.testing.*
 import kotlinx.coroutines.*
-import java.io.*
-import java.lang.reflect.*
-import java.util.concurrent.*
-import kotlin.coroutines.*
-import kotlin.test.*
+import java.io.Closeable
+import java.lang.reflect.Method
+import java.time.ZonedDateTime
+import java.util.concurrent.Executors
+import kotlin.coroutines.CoroutineContext
+import kotlin.test.AfterTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
 
 class ServerJacksonBlockingTest {
     private val dispatcher = UnsafeDispatcher()
@@ -60,6 +64,29 @@ class ServerJacksonBlockingTest {
         }
     }
 
+    @Test
+    fun testJacksonModuleNotRegistered() = testApplication {
+        environment {
+            config = MapApplicationConfig("ktor.test.throwOnException" to "false")
+        }
+        install(ContentNegotiation) {
+            jackson()
+        }
+        routing {
+            get("/") {
+                call.respond(Message(msg = "Hi", time = ZonedDateTime.now()))
+            }
+        }
+
+        runBlocking {
+            client.get("/").apply {
+                assertEquals(HttpStatusCode.InternalServerError, status)
+            }
+        }
+    }
+
+    data class Message(val msg: String, val time: ZonedDateTime)
+
     data class K(var i: Int)
 
     private class UnsafeDispatcher : CoroutineDispatcher(), Closeable {