improved sign handling

src/main/java/net/minecraft/server/NetServerHandler.java

@@ -855,16 +855,15 @@ public class NetServerHandler extends NetHandler implements ICommandListener {
         // CraftBukkit start
         if (((WorldServer) this.player.world).isLoaded(packet130updatesign.x, packet130updatesign.y, packet130updatesign.z)) {
             TileEntity tileentity = ((WorldServer) this.player.world).getTileEntity(packet130updatesign.x, packet130updatesign.y, packet130updatesign.z);
-            // CraftBukkit end
 
             if (tileentity instanceof TileEntitySign) {
                 TileEntitySign tileentitysign = (TileEntitySign) tileentity;
 
                 if (!tileentitysign.a()) {
                     this.minecraftServer.c("Player " + this.player.name + " just tried to change non-editable sign");
+                    this.sendPacket(new Packet130UpdateSign(packet130updatesign.x, packet130updatesign.y, packet130updatesign.z, tileentitysign.lines));
                     return;
                 }
-            }
 
                 int i;
                 int j;
@@ -890,35 +889,26 @@ public class NetServerHandler extends NetHandler implements ICommandListener {
                 if (tileentity instanceof TileEntitySign) {
                     j = packet130updatesign.x;
                     int k = packet130updatesign.y;
-
                     i = packet130updatesign.z;
-                TileEntitySign tileentitysign1 = (TileEntitySign) tileentity;
 
-                // CraftBukkit start - SIGN_CHANGE hook
                     Player player = server.getPlayer(this.player);
                     SignChangeEvent event = new SignChangeEvent((CraftBlock) player.getWorld().getBlockAt(j, k, i), server.getPlayer(this.player), packet130updatesign.lines);
                     server.getPluginManager().callEvent(event);
 
-                if (event.isCancelled()) {
+                    if (!event.isCancelled()) {
-                    // Normally we would return here, but we have to update the sign with blank text if it's been cancelled
-                    // Otherwise the client will have bad text on their sign (client shows text changes as they type)
                         for (int l = 0; l < 4; ++l) {
-                        event.setLine(l, "");
+                            tileentitysign.lines[l] = event.getLine(l);
                         }
-                }
+                        tileentitysign.setEditable(false);
-                // CraftBukkit end
-
-                for (int l = 0; l < 4; ++l) {
-                    tileentitysign1.lines[l] = event.getLine(l);
-                    // CraftBukkit
                     }
 
-                tileentitysign1.update();
+                    tileentitysign.update();
-                // CraftBukkit
                     ((WorldServer) this.player.world).notify(j, k, i);
                 }
             }
         }
+        // CraftBukkit end
+    }
 
     public boolean c() {
         return true;

src/main/java/net/minecraft/server/TileEntitySign.java

@@ -47,4 +47,10 @@ public class TileEntitySign extends TileEntity {
     public boolean a() {
         return this.c;
     }
+
+    // CraftBukkit start
+    public void setEditable(boolean editable) {
+        this.c = editable;
+    }
+    // CraftBukkit end
 }