Reproduce malformed feedback event handling in the UI

tools/chatgui-android/app/src/main/java/com/utun/chat/data/Feedback.kt

@@ -2,6 +2,8 @@ package com.utun.chat.data
 
 import org.json.JSONArray
 import org.json.JSONObject
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
 
 /* Модели снимка chat_feedback_snapshot и подготовка форм опроса для общего командного API core.
  * Сетевой формат/подписи/подсчёт голосов остаются в C; здесь только JSON-разбор и проверка готового ввода UI. */
@@ -23,6 +25,24 @@ data class PollState(val question: String, val multiple: Boolean, val allowCusto
  * poll=null допустимо для обычного сообщения или ещё отсутствующего исходного опроса. */
 data class FeedbackState(val messageId: String, val pending: Boolean, val reactions: List<ReactionState>, val poll: PollState?)
 
+data class FeedbackChangedEvent(val channelId: String, val messageId: String, val kind: Int)
+data class FeedbackResultEvent(val requestId: Long, val success: Boolean, val json: JSONObject)
+
+fun parseFeedbackChangedEvent(data: ByteArray?): FeedbackChangedEvent? {
+    if (data == null || data.size < 34) return null
+    val size = data[0].toInt() and 255
+    require(data.size == size + 34) { "invalid change event" }
+    val channel = String(data, 1, size, Charsets.UTF_8)
+    val id = data.copyOfRange(size + 1, size + 33).joinToString("") { "%02x".format(it.toInt() and 255) }
+    return FeedbackChangedEvent(channel, id, data.last().toInt() and 255)
+}
+
+fun parseFeedbackResultEvent(data: ByteArray?): FeedbackResultEvent? {
+    if (data == null || data.size < 9) return null
+    val id = ByteBuffer.wrap(data).order(ByteOrder.LITTLE_ENDIAN).long
+    return FeedbackResultEvent(id, data[8].toInt() != 0, JSONObject(String(data, 9, data.size - 9, Charsets.UTF_8)))
+}
+
 /** Нормализованный ответ формы: отправляются только активные поля; пустой выбор/текст отменяет голос. */
 data class PollVoteDraft(val choices: List<Int>, val custom: String)
 

tools/chatgui-android/app/src/main/java/com/utun/chat/viewmodel/ChatViewModel.kt

@@ -504,22 +504,19 @@ class ChatViewModel : ViewModel() {
                 if (data[16].toInt() == 0) _radioMuteFailed.value = true
             }
             53 -> { /* FEEDBACK_CHANGED: channel, message_id, kind. */
-                if (data == null || data.size < 34) return
-                val size = data[0].toInt() and 255
-                if (data.size != size + 34) { LogManager.addLog("ERROR", "POLL", "invalid change event"); return }
-                val channel = String(data, 1, size, Charsets.UTF_8)
-                if (_currentChannel.value?.id != channel) return
-                val id = data.copyOfRange(size + 1, size + 33).joinToString("") { "%02x".format(it.toInt() and 255) }
-                sendInteraction(JSONObject().put("cmd", "feedback").put("ch", channel).put("message_id", id), false)
+                try {
+                    val event = parseFeedbackChangedEvent(data) ?: return
+                    if (_currentChannel.value?.id != event.channelId) return
+                    sendInteraction(JSONObject().put("cmd", "feedback").put("ch", event.channelId).put("message_id", event.messageId), false)
+                } catch (e: Exception) { LogManager.addLog("ERROR", "POLL", "invalid change event bytes=${data?.size}: ${e.message}") }
             }
             54 -> { /* FEEDBACK_RESULT: request_id:8LE, success, UTF-8 JSON. */
-                if (data == null || data.size < 9) return
                 try {
-                    val id = java.nio.ByteBuffer.wrap(data, 0, 8).order(java.nio.ByteOrder.LITTLE_ENDIAN).long
-                    val result = JSONObject(String(data, 9, data.size - 9, Charsets.UTF_8))
-                    if (data[8].toInt() == 0) {
-                        LogManager.addLog("ERROR", "POLL", "command failed: ${result.optString("error")}")
-                        if (id != 0L) _interactionFailed.value = true
+                    val event = parseFeedbackResultEvent(data) ?: return
+                    val result = event.json
+                    if (!event.success) {
+                        LogManager.addLog("ERROR", "POLL", "command failed request=${event.requestId}: ${result.optString("error")}")
+                        if (event.requestId != 0L) _interactionFailed.value = true
                     } else if (result.has("catalog")) {
                         val values = result.getJSONArray("catalog")
                         _reactionCatalog.value = (0 until values.length()).map { index -> values.getJSONObject(index).let {
@@ -537,7 +534,10 @@ class ChatViewModel : ViewModel() {
                             _messages.update { rows -> rows.map { if (it.messageId == state.messageId) it.copy(feedback = state) else it } }
                         }
                     }
-                } catch (e: Exception) { LogManager.addLog("ERROR", "POLL", "invalid result: ${e.message}"); _interactionFailed.value = true }
+                } catch (e: Exception) {
+                    LogManager.addLog("ERROR", "POLL", "invalid result bytes=${data?.size}: ${e.message}")
+                    _interactionFailed.value = true
+                }
             }
             9 -> { /* DB_READY */
                 if (dbReady) return

tools/chatgui-android/app/src/test/java/com/utun/chat/data/FeedbackEventTest.kt

@@ -0,0 +1,73 @@
+package com.utun.chat.data
+
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.nio.charset.CharacterCodingException
+import org.junit.Assert.*
+import org.junit.Test
+
+/** Настоящий wire-разбор, используемый ViewModel; формат фиксируют chat_event.h и C-производители событий. */
+class FeedbackEventTest {
+    private fun changed(channel: String = "123", kind: Int = 1): ByteArray {
+        val text = channel.toByteArray(Charsets.UTF_8)
+        return byteArrayOf(text.size.toByte()) + text + ByteArray(32) { it.toByte() } + byteArrayOf(kind.toByte())
+    }
+    private fun result(id: Long = 7, flag: Int = 1, text: ByteArray = "{}".toByteArray()): ByteArray =
+        ByteBuffer.allocate(9 + text.size).order(ByteOrder.LITTLE_ENDIAN).putLong(id).put(flag.toByte()).put(text).array()
+
+    @Test fun changedEventKeepsCanonicalChannelMessageAndFeedbackKind() {
+        val event = requireNotNull(parseFeedbackChangedEvent(changed("9223372036854775807", 2)))
+        assertEquals("9223372036854775807", event.channelId); assertEquals(2, event.kind)
+        assertEquals("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", event.messageId)
+    }
+
+    @Test fun truncatedChangedEventsFailInsteadOfBeingSilentlyIgnored() {
+        assertThrows(IllegalArgumentException::class.java) { parseFeedbackChangedEvent(null) }
+        for (size in 0..34) assertThrows(IllegalArgumentException::class.java) { parseFeedbackChangedEvent(ByteArray(size)) }
+        val valid = changed()
+        assertThrows(IllegalArgumentException::class.java) { parseFeedbackChangedEvent(valid.copyOf(valid.size - 1)) }
+        assertThrows(IllegalArgumentException::class.java) { parseFeedbackChangedEvent(valid + byteArrayOf(0)) }
+    }
+
+    @Test fun invalidChannelAndUnknownKindCannotTriggerASnapshotRequest() {
+        for (channel in listOf("", "0", "01", "-1", "+1", "1a", "é", "9223372036854775808", "1".repeat(20))) {
+            assertThrows(IllegalArgumentException::class.java) { parseFeedbackChangedEvent(changed(channel)) }
+        }
+        for (kind in listOf(0, 3, 255)) {
+            assertThrows(IllegalArgumentException::class.java) { parseFeedbackChangedEvent(changed(kind = kind)) }
+        }
+    }
+
+    @Test fun resultPreservesAllRequestBitsAndUnicodeErrorText() {
+        val id = 0xfedcba9876543210uL.toLong()
+        val event = requireNotNull(parseFeedbackResultEvent(result(id, 0, "{\"error\":\"Отказ 😀\"}".toByteArray())))
+        assertEquals(id, event.requestId); assertFalse(event.success); assertEquals("Отказ 😀", event.json.getString("error"))
+        val background = requireNotNull(parseFeedbackResultEvent(result(0)))
+        assertEquals(0L, background.requestId); assertTrue(background.success)
+    }
+
+    @Test fun truncatedResultAndEmptyJsonFailForTheCallerToReport() {
+        assertThrows(IllegalArgumentException::class.java) { parseFeedbackResultEvent(null) }
+        for (size in 0..9) assertThrows(IllegalArgumentException::class.java) { parseFeedbackResultEvent(ByteArray(size)) }
+    }
+
+    @Test fun successFlagMustBeExactlyZeroOrOne() {
+        for (flag in listOf(2, 127, 255)) {
+            assertThrows(IllegalArgumentException::class.java) { parseFeedbackResultEvent(result(flag = flag)) }
+        }
+    }
+
+    @Test fun invalidUtf8AndMalformedJsonAreNotReplacedByAValidSnapshot() {
+        val corrupt = "{\"text\":\"".toByteArray() + byteArrayOf(0xff.toByte()) + "\"}".toByteArray()
+        assertThrows(CharacterCodingException::class.java) { parseFeedbackResultEvent(result(text = corrupt)) }
+        assertThrows(Exception::class.java) { parseFeedbackResultEvent(result(text = "{broken}".toByteArray())) }
+    }
+
+    @Test fun committedAckAndCatalogRemainDifferentFromASnapshot() {
+        val ack = "{\"ch\":\"123\",\"message_id\":\"${"ab".repeat(32)}\",\"committed\":true,\"snapshot_pending\":true}"
+        val event = requireNotNull(parseFeedbackResultEvent(result(text = ack.toByteArray())))
+        assertTrue(event.success); assertTrue(event.json.getBoolean("committed")); assertTrue(event.json.getBoolean("snapshot_pending"))
+        val catalog = requireNotNull(parseFeedbackResultEvent(result(text = "{\"catalog\":[]}".toByteArray())))
+        assertTrue(catalog.json.has("catalog")); assertFalse(catalog.json.has("message_id"))
+    }
+}