KTOR-8581 Avoid passing the max parameter of the decode method and catch the MalformedInputException (#4928)

Author: Stexxe

ktor-client/ktor-client-plugins/ktor-client-logging/common/src/io/ktor/client/plugins/logging/Logging.kt

@@ -151,17 +151,25 @@ public val Logging: ClientPlugin<LoggingConfig> = createClientPlugin("Logging",
         }
 
         val buffer = Buffer().apply { writeFully(firstChunk, 0, firstReadSize) }
-        val firstChunkText = charset.newDecoder().decode(buffer, firstReadSize)
 
-        var lastCharIndex = -1
-        for (ch in firstChunkText) {
-            lastCharIndex += 1
+        val firstChunkText = try {
+            charset.newDecoder().decode(buffer)
+        } catch (_: MalformedInputException) {
+            isBinary = true
+            ""
         }
 
-        for ((i, ch) in firstChunkText.withIndex()) {
-            if (ch == '\ufffd' && i != lastCharIndex) {
-                isBinary = true
-                break
+        if (!isBinary) {
+            var lastCharIndex = -1
+            for (ch in firstChunkText) {
+                lastCharIndex += 1
+            }
+
+            for ((i, ch) in firstChunkText.withIndex()) {
+                if (ch == '\ufffd' && i != lastCharIndex) {
+                    isBinary = true
+                    break
+                }
             }
         }
 

ktor-client/ktor-client-tests/common/test/io/ktor/client/tests/LoggingTest.kt

@@ -24,6 +24,7 @@ import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertNotNull
 import kotlin.test.assertTrue
+import kotlin.test.fail
 
 @OptIn(DelicateCoroutinesApi::class)
 class LoggingTest : ClientLoader() {
@@ -556,4 +557,44 @@ class LoggingTest : ClientLoader() {
             testLogger.verify()
         }
     }
+
+    @Test
+    fun testBinaryDecodingWithOkHttpFormat() = clientTests(except("web:Js")) {
+        val lines = mutableListOf<String>()
+        config {
+            Logging {
+                logger = object : Logger {
+                    override fun log(message: String) {
+                        lines.addAll(message.split("\n"))
+                    }
+                }
+                level = LogLevel.BODY
+                format = LoggingFormat.OkHttp
+            }
+        }
+
+        test { client ->
+            client.get("$TEST_SERVER/content/binary")
+        }
+
+        after {
+            val iter = lines.iterator()
+
+            assertEquals("--> GET /content/binary", iter.next())
+            assertEquals("Accept-Charset: UTF-8", iter.next())
+            assertEquals("Accept: */*", iter.next())
+            assertEquals("--> END GET", iter.next())
+            assertMatch(Regex("<-- 200 OK /content/binary \\(\\d+ms\\)"), iter.next())
+
+            val lastLine = lines.find { it.startsWith("<-- END HTTP") }
+            assertNotNull(lastLine)
+            assertMatch(Regex("<-- END HTTP \\(\\d+ms, binary 8-byte body omitted\\)"), lastLine)
+        }
+    }
+
+    private fun assertMatch(regex: Regex, actual: String) {
+        if (!regex.matches(actual)) {
+            fail("Regex $regex doesn't match $actual")
+        }
+    }
 }

ktor-test-server/src/main/kotlin/test/server/tests/Content.kt

@@ -111,6 +111,12 @@ internal fun Application.contentTestServer() {
                     }
                 )
             }
+
+            get("/binary") {
+                call.respondBytes(contentType = ContentType.Image.PNG) {
+                    byteArrayOf((0x89).toByte(), 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a)
+                }
+            }
         }
     }
 }