KTOR-4722 renderSetCookieHeader should not encode extensions (#3172)

Author: rsinukov1

ktor-http/common/src/io/ktor/http/Cookie.kt

@@ -157,8 +157,8 @@ public fun renderSetCookieHeader(
 
         cookiePartFlag("Secure", secure),
         cookiePartFlag("HttpOnly", httpOnly)
-    ) + extensions.map { cookiePartExt(it.key.assertCookieName(), it.value, encoding) } +
-        if (includeEncoding) cookiePartExt("\$x-enc", encoding.name, CookieEncoding.RAW) else ""
+    ) + extensions.map { cookiePartExt(it.key.assertCookieName(), it.value) } +
+        if (includeEncoding) cookiePartExt("\$x-enc", encoding.name) else ""
     ).filter { it.isNotEmpty() }
     .joinToString("; ")
 
@@ -221,7 +221,7 @@ private inline fun cookiePartFlag(name: String, value: Boolean) =
     if (value) name else ""
 
 @Suppress("NOTHING_TO_INLINE")
-private inline fun cookiePartExt(name: String, value: String?, encoding: CookieEncoding) =
-    if (value == null) cookiePartFlag(name, true) else cookiePart(name, value, encoding)
+private inline fun cookiePartExt(name: String, value: String?) =
+    if (value == null) cookiePartFlag(name, true) else cookiePart(name, value, CookieEncoding.RAW)
 
 private fun String.toIntClamping(): Int = toLong().coerceIn(0L, Int.MAX_VALUE.toLong()).toInt()

ktor-http/common/test/io/ktor/tests/http/RenderSetCookieTest.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2014-2022 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.tests.http
+
+import io.ktor.http.*
+import kotlin.test.*
+
+class RenderSetCookieTest {
+
+    @Test
+    fun renderCookieDoesntEncodeExtensions() {
+        val cookie = Cookie(
+            "name",
+            "value",
+            encoding = CookieEncoding.BASE64_ENCODING,
+            extensions = mapOf("foo" to "bar")
+        )
+        val rendered = renderSetCookieHeader(cookie)
+        assertEquals("name=dmFsdWU=; foo=bar; \$x-enc=BASE64_ENCODING", rendered)
+    }
+
+    @Test
+    fun renderCookieThrowsOnNotEncodedExtensions() {
+        val cookie = Cookie(
+            "name",
+            "value",
+            encoding = CookieEncoding.BASE64_ENCODING,
+            extensions = mapOf("foo" to "b,ar")
+        )
+        assertFailsWith<IllegalArgumentException> {
+            renderSetCookieHeader(cookie)
+        }
+    }
+}