From fb2cc8ae3e099bf1bcb62322cdad4aacf98287b0 Mon Sep 17 00:00:00 2001
From: Mariia Skripchenko <61115099+marychatte@users.noreply.github.com>
Date: Tue, 3 Dec 2024 14:03:34 +0100
Subject: [PATCH] KTOR-7876 Fix Sink.writeText corrupts long streams for Jetty
 server

---
 .../src/io/ktor/utils/io/core/Strings.kt       |  6 +-----
 .../server/jetty/jakarta/JettyEngineTest.kt    | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/ktor-io/common/src/io/ktor/utils/io/core/Strings.kt b/ktor-io/common/src/io/ktor/utils/io/core/Strings.kt
index 9a1d694f7b9..8777cad734b 100644
--- a/ktor-io/common/src/io/ktor/utils/io/core/Strings.kt
+++ b/ktor-io/common/src/io/ktor/utils/io/core/Strings.kt
@@ -89,7 +89,7 @@ public fun Source.readTextExactCharacters(charactersCount: Int, charset: Charset
 }
 
 /**
- * Writes [text] characters in range \[[fromIndex] .. [toIndex]) with the specified [charset]
+ * Writes [text] characters in range [fromIndex] .. [toIndex]) with the specified [charset]
  */
 public fun Sink.writeText(
     text: CharSequence,
@@ -97,10 +97,6 @@ public fun Sink.writeText(
     toIndex: Int = text.length,
     charset: Charset = Charsets.UTF_8
 ) {
-    if (charset === Charsets.UTF_8) {
-        return writeString(text.toString(), fromIndex, toIndex)
-    }
-
     charset.newEncoder().encodeToImpl(this, text, fromIndex, toIndex)
 }
 
diff --git a/ktor-server/ktor-server-jetty-jakarta/jvm/test/io/ktor/tests/server/jetty/jakarta/JettyEngineTest.kt b/ktor-server/ktor-server-jetty-jakarta/jvm/test/io/ktor/tests/server/jetty/jakarta/JettyEngineTest.kt
index a836c2c423d..a45bd6f41d1 100644
--- a/ktor-server/ktor-server-jetty-jakarta/jvm/test/io/ktor/tests/server/jetty/jakarta/JettyEngineTest.kt
+++ b/ktor-server/ktor-server-jetty-jakarta/jvm/test/io/ktor/tests/server/jetty/jakarta/JettyEngineTest.kt
@@ -10,6 +10,7 @@ import io.ktor.server.response.*
 import io.ktor.server.routing.*
 import io.ktor.server.servlet.jakarta.*
 import io.ktor.server.testing.suites.*
+import io.ktor.utils.io.*
 import jakarta.servlet.http.*
 import org.eclipse.jetty.server.*
 import org.eclipse.jetty.server.handler.*
@@ -55,6 +56,23 @@ class JettyHttpServerJvmTest : HttpServerJvmTestSuite<JettyApplicationEngine, Je
         }
     }
 
+    @Test
+    fun testWriteNonASCIIChars() = runTest {
+        val input = (1..6000).map { if (it % 2 == 0) 'å' else (64 + it % 10).toChar() }.joinToString("")
+
+        createAndStartServer {
+            get {
+                call.respondBytesWriter {
+                    writeStringUtf8(input)
+                }
+            }
+        }
+
+        withUrl("/", {}) {
+            assertEquals(input, call.response.bodyAsText())
+        }
+    }
+
     private fun Server.addAttributesHandler() {
         addEventListener(
             object : LifeCycle.Listener {