Fix message limit

mirai-core/src/commonMain/kotlin/contact/GroupImpl.kt

@@ -32,7 +32,6 @@ import net.mamoe.mirai.internal.network.protocol.packet.chat.receive.createToGro
 import net.mamoe.mirai.internal.network.protocol.packet.chat.voice.PttStore
 import net.mamoe.mirai.internal.network.protocol.packet.list.ProfileService
 import net.mamoe.mirai.internal.utils.GroupPkgMsgParsingCache
-import net.mamoe.mirai.internal.utils.estimateLength
 import net.mamoe.mirai.message.MessageReceipt
 import net.mamoe.mirai.message.data.*
 import net.mamoe.mirai.utils.*
@@ -154,17 +153,15 @@ internal class GroupImpl(
                 throw EventCancelledException("exception thrown when broadcasting GroupMessagePreSendEvent", it)
             }.message.asMessageChain()
 
-            val length = chain.estimateLength(this, 703) // 阈值为700左右，限制到3的倍数
+            var length: Int = 0
-            var imageCnt = 0 // 通过下方逻辑短路延迟计算
+            var imageCnt: Int = 0
+            chain.verityLength(message, this, lengthCallback = {
+                length = it
+            }, imageCntCallback = {
+                imageCnt = it
+            })
 
-            if (length > 5000 || chain.count { it is Image }.apply { imageCnt = this } > 50) {
+            if (length > 702 || imageCnt > 2) {  // 阈值为700左右，限制到3的倍数
-                throw MessageTooLargeException(
-                    this, message, chain,
-                    "message(${chain.joinToString("", limit = 10)}) is too large. Allow up to 50 images or 5000 chars"
-                )
-            }
-
-            if (length > 702 || imageCnt > 2) {
                 return MiraiImpl.lowLevelSendGroupLongOrForwardMessage(
                     bot,
                     this.id,

mirai-core/src/commonMain/kotlin/contact/util.kt

@@ -20,6 +20,7 @@ import net.mamoe.mirai.internal.message.MessageSourceToFriendImpl
 import net.mamoe.mirai.internal.message.ensureSequenceIdAvailable
 import net.mamoe.mirai.internal.network.protocol.packet.chat.receive.MessageSvcPbSendMsg
 import net.mamoe.mirai.internal.network.protocol.packet.chat.receive.createToFriend
+import net.mamoe.mirai.internal.utils.estimateLength
 import net.mamoe.mirai.message.*
 import net.mamoe.mirai.message.data.*
 import net.mamoe.mirai.utils.cast
@@ -49,6 +50,7 @@ internal suspend fun <T : User> Friend.sendMessageImpl(
     }.getOrElse {
         throw EventCancelledException("exception thrown when broadcasting FriendMessagePreSendEvent", it)
     }.message.asMessageChain()
+    chain.verityLength(message, this, {}, {})
 
     chain.firstIsInstanceOrNull<QuoteReply>()?.source?.ensureSequenceIdAvailable()
 
@@ -89,6 +91,29 @@ internal fun Contact.logMessageSent(message: Message) {
     }
 }
 
+internal inline fun MessageChain.verityLength(
+    message: Message, target: Contact,
+    lengthCallback: (Int) -> Unit,
+    imageCntCallback: (Int) -> Unit
+) {
+    contract {
+        callsInPlace(lengthCallback, InvocationKind.EXACTLY_ONCE)
+        callsInPlace(imageCntCallback, InvocationKind.EXACTLY_ONCE)
+    }
+
+    val chain = this
+    val length = estimateLength(target, 5001)
+    lengthCallback(length)
+    if (length > 5000 || count { it is Image }.apply { imageCntCallback(this) } > 50) {
+        throw MessageTooLargeException(
+            target, message, this,
+            "message(${
+                chain.joinToString("", limit = 10)
+            }) is too large. Allow up to 50 images or 5000 chars"
+        )
+    }
+}
+
 @Suppress("RemoveRedundantQualifierName") // compiler bug
 internal fun net.mamoe.mirai.event.events.MessageEvent.logMessageReceived() {
     fun renderGroupMessage(group: Group, senderName: String, sender: Member, message: MessageChain): String {