Don’t support older versions if protocol support is installed, fixes #615

bukkit/src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -253,4 +253,9 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform {
 
         return platformSpecific;
     }
+
+    @Override
+    public boolean isOldClientsAllowed() {
+        return !protocolSupport; // Use protocolsupport for older clients
+    }
 }

bungee/src/main/java/us/myles/ViaVersion/BungeePlugin.java

@@ -155,6 +155,11 @@ public class BungeePlugin extends Plugin implements ViaPlatform, Listener {
         return platformSpecific;
     }
 
+    @Override
+    public boolean isOldClientsAllowed() {
+        return true;
+    }
+
     @EventHandler
     public void onQuit(PlayerDisconnectEvent e) {
         Via.getManager().removePortedClient(e.getPlayer().getUniqueId());

common/src/main/java/us/myles/ViaVersion/api/platform/ViaPlatform.java

@@ -140,4 +140,12 @@ public interface ViaPlatform<T> {
      * @return The json data
      */
     JsonObject getDump();
+
+    /**
+     * Get if older clients are allowed to be used using ViaVersion.
+     * (Only 1.9 on 1.9.2 server is supported by ViaVersion alone)
+     *
+     * @return True if allowed
+     */
+    boolean isOldClientsAllowed();
 }

common/src/main/java/us/myles/ViaVersion/protocols/base/BaseProtocol.java

@@ -72,7 +72,12 @@ public class BaseProtocol extends Protocol {
                                 ProtocolRegistry.SERVER_PROTOCOL = protocolVersion;
 
                             int protocol = Via.getManager().getProviders().get(VersionProvider.class).getServerProtocol(wrapper.user());
-                            List<Pair<Integer, Protocol>> protocols = ProtocolRegistry.getProtocolPath(info.getProtocolVersion(), protocol);
+                            List<Pair<Integer, Protocol>> protocols = null;
+
+                            // Only allow newer clients or (1.9.2 on 1.9.4 server if the server supports it)
+                            if (info.getProtocolVersion() >= protocol || Via.getPlatform().isOldClientsAllowed()) {
+                                protocols = ProtocolRegistry.getProtocolPath(info.getProtocolVersion(), protocol);
+                            }
 
                             if (protocols != null) {
                                 if (protocolVersion != 9999) {
@@ -163,7 +168,13 @@ public class BaseProtocol extends Protocol {
                         info.setProtocolVersion(protVer);
                         // Choose the pipe
                         int protocol = Via.getManager().getProviders().get(VersionProvider.class).getServerProtocol(wrapper.user());
-                        List<Pair<Integer, Protocol>> protocols = ProtocolRegistry.getProtocolPath(info.getProtocolVersion(), protocol);
+                        List<Pair<Integer, Protocol>> protocols = null;
+
+                        // Only allow newer clients or (1.9.2 on 1.9.4 server if the server supports it)
+                        if (info.getProtocolVersion() >= protocol || Via.getPlatform().isOldClientsAllowed()) {
+                            protocols = ProtocolRegistry.getProtocolPath(info.getProtocolVersion(), protocol);
+                        }
+
                         ProtocolPipeline pipeline = wrapper.user().get(ProtocolInfo.class).getPipeline();
                         if (protocols != null) {
                             for (Pair<Integer, Protocol> prot : protocols) {

sponge/src/main/java/us/myles/ViaVersion/SpongePlugin.java

@@ -199,4 +199,9 @@ public class SpongePlugin implements ViaPlatform {
 
         return platformSpecific;
     }
+
+    @Override
+    public boolean isOldClientsAllowed() {
+        return true;
+    }
 }