Use strong reference in message events, fix #303

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/ContactMessage.kt

@@ -73,7 +73,6 @@ abstract class MessagePacketBase<out TSender : User, out TSubject : Contact> : P
     /**
      * 接受到这条消息的
      */
-    @WeakRefProperty
     abstract override val bot: Bot
 
     /**
@@ -85,7 +84,6 @@ abstract class MessagePacketBase<out TSender : User, out TSubject : Contact> : P
      *
      * 在回复消息时, 可通过 [subject] 作为回复对象
      */
-    @WeakRefProperty
     abstract val subject: TSubject
 
     /**
@@ -93,7 +91,6 @@ abstract class MessagePacketBase<out TSender : User, out TSubject : Contact> : P
      *
      * 在好友消息时为 [Friend] 的实例, 在群消息时为 [Member] 的实例
      */
-    @WeakRefProperty
     abstract val sender: TSender
 
     abstract val senderName: String

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/FriendMessage.kt

@@ -18,14 +18,12 @@ import net.mamoe.mirai.message.data.MessageChain
 import net.mamoe.mirai.message.data.MessageSource
 import net.mamoe.mirai.message.data.OnlineMessageSource
 import net.mamoe.mirai.message.data.source
-import net.mamoe.mirai.utils.getValue
-import net.mamoe.mirai.utils.unsafeWeakRef
 
 /**
  * 好友消息事件
  */
 class FriendMessage constructor(
-    sender: Friend,
+    override val sender: Friend,
     override val message: MessageChain,
     override val time: Int
 ) : ContactMessage(), BroadcastControllable {
@@ -34,7 +32,6 @@ class FriendMessage constructor(
         check(source is OnlineMessageSource.Incoming.FromFriend) { "source provided to a FriendMessage must be an instance of OnlineMessageSource.Incoming.FromFriend" }
     }
 
-    override val sender: Friend by sender.unsafeWeakRef()
     override val bot: Bot get() = sender.bot
     override val subject: Friend get() = sender
     override val senderName: String get() = sender.nick

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/GroupMessage.kt

@@ -15,8 +15,6 @@ import net.mamoe.mirai.contact.Member
 import net.mamoe.mirai.contact.MemberPermission
 import net.mamoe.mirai.event.Event
 import net.mamoe.mirai.message.data.*
-import net.mamoe.mirai.utils.getValue
-import net.mamoe.mirai.utils.unsafeWeakRef
 
 /**
  * 群消息事件
@@ -30,7 +28,7 @@ class GroupMessage(
      * 发送方权限.
      */
     val permission: MemberPermission,
-    sender: Member,
+    override val sender: Member,
     override val message: MessageChain,
     override val time: Int
 ) : ContactMessage(), Event {
@@ -39,7 +37,6 @@ class GroupMessage(
         check(source is OnlineMessageSource.Incoming.FromGroup) { "source provided to a GroupMessage must be an instance of OnlineMessageSource.Incoming.FromGroup" }
     }
 
-    override val sender: Member by sender.unsafeWeakRef()
     val group: Group get() = sender.group
     override val bot: Bot get() = sender.bot
 

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/TempMessage.kt

@@ -10,15 +10,13 @@ import net.mamoe.mirai.message.data.MessageSource
 import net.mamoe.mirai.message.data.OnlineMessageSource
 import net.mamoe.mirai.message.data.source
 import net.mamoe.mirai.utils.SinceMirai
-import net.mamoe.mirai.utils.getValue
-import net.mamoe.mirai.utils.unsafeWeakRef
 
 /**
  * 临时会话消息
  */
 @SinceMirai("0.35.0")
 class TempMessage(
-    sender: Member,
+    override val sender: Member,
     override val message: MessageChain,
     override val time: Int
 ) : ContactMessage(), BroadcastControllable {
@@ -27,7 +25,6 @@ class TempMessage(
         check(source is OnlineMessageSource.Incoming.FromTemp) { "source provided to a TempMessage must be an instance of OnlineMessageSource.Incoming.FromTemp" }
     }
 
-    override val sender: Member by sender.unsafeWeakRef()
     override val bot: Bot get() = sender.bot
     override val subject: Member get() = sender
     inline val group: Group get() = sender.group