fix(mod): add MixinServerGamePacketListenerImplKt.kt to git

versions/src/main/kotlin/su/plo/slib/mod/mixinkt/MixinServerGamePacketListenerImplKt.kt

@@ -0,0 +1,48 @@
+package su.plo.slib.mod.mixinkt
+
+//#if FORGE
+//#if MC<12002
+//$$ import io.netty.util.AsciiString
+//$$ import net.minecraft.network.FriendlyByteBuf
+//$$ import net.minecraft.network.protocol.game.ServerboundCustomPayloadPacket
+//$$ import net.minecraft.resources.ResourceLocation
+//$$ import net.minecraft.server.level.ServerPlayer
+//$$ import su.plo.slib.mod.channel.RegisterChannelHandler
+//$$
+//$$ object MixinServerGamePacketListenerImplKt {
+//$$
+//$$     private val REGISTER = ResourceLocation("minecraft:register")
+//$$
+//$$     fun handleCustomPayload(player: ServerPlayer, packet: ServerboundCustomPayloadPacket) {
+//$$         val packetId = packet.identifier
+//$$         if (packetId != REGISTER) return
+//$$
+//$$         val channels = parseChannels(packet.data)
+//$$         RegisterChannelHandler.firePlayerRegisterChannels(player, channels)
+//$$     }
+//$$
+//$$     private fun parseChannels(buf: FriendlyByteBuf): List<String> {
+//$$         val channels = ArrayList<String>()
+//$$         val active = StringBuilder()
+//$$
+//$$         while (buf.isReadable) {
+//$$             val byte = buf.readByte()
+//$$
+//$$             if (byte != 0.toByte()) {
+//$$                 active.append(AsciiString.b2c(byte))
+//$$                 continue
+//$$             }
+//$$
+//$$             val channel = active.toString()
+//$$             if (ResourceLocation.isValidResourceLocation(channel)) {
+//$$                 channels.add(channel)
+//$$             }
+//$$
+//$$             active.clear()
+//$$         }
+//$$
+//$$         return channels
+//$$     }
+//$$ }
+//#endif
+//#endif