From f63ca316d774293521154e542efc730e64753de8 Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Fri, 6 May 2016 13:19:11 +1000
Subject: [PATCH] Reject invalid terrain.png (non square, non power of 2)
 instead of crashing. (Thanks 123DMWM)

---
 ClassicalSharp/Game/Game.cs                        | 11 +++++++++--
 ClassicalSharp/Network/INetworkProcessor.cs        |  4 ++--
 ClassicalSharp/TexturePack/Animations.cs           |  4 ++--
 ClassicalSharp/TexturePack/TexturePackExtractor.cs |  4 +++-
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/ClassicalSharp/Game/Game.cs b/ClassicalSharp/Game/Game.cs
index e6fbd1dff..5d0abacfa 100644
--- a/ClassicalSharp/Game/Game.cs
+++ b/ClassicalSharp/Game/Game.cs
@@ -34,9 +34,16 @@ namespace ClassicalSharp {
 			TerrainAtlas1D.UpdateState( TerrainAtlas );
 		}
 		
-		public void ChangeTerrainAtlas( Bitmap newAtlas ) {
-			LoadAtlas( newAtlas );
+		public bool ChangeTerrainAtlas( Bitmap atlas ) {
+			bool pow2 = Utils.IsPowerOf2( atlas.Width ) && Utils.IsPowerOf2( atlas.Height );
+			if( !pow2 || atlas.Width != atlas.Height ) {
+				Chat.Add( "&cCurrent texture pack has an invalid terrain.png" );
+				Chat.Add( "&cWidth and length must be the same, and also powers of two." );
+				return false;
+			}
+			LoadAtlas( atlas );
 			Events.RaiseTerrainAtlasChanged();
+			return true;
 		}
 		
 		public void Run() { window.Run(); }
diff --git a/ClassicalSharp/Network/INetworkProcessor.cs b/ClassicalSharp/Network/INetworkProcessor.cs
index 82787d670..a37907d1a 100644
--- a/ClassicalSharp/Network/INetworkProcessor.cs
+++ b/ClassicalSharp/Network/INetworkProcessor.cs
@@ -134,7 +134,7 @@ namespace ClassicalSharp {
 						Utils.LogDebug( "Converting terrain atlas to 32bpp image" );
 						game.Drawer2D.ConvertTo32Bpp( ref bmp );
 					}
-					game.ChangeTerrainAtlas( bmp );
+					if( !game.ChangeTerrainAtlas( bmp ) ) { bmp.Dispose(); return; }
 					TextureCache.AddToCache( item.Url, bmp );
 					TextureCache.AddETagToCache( item.Url, item.ETag, game.ETags );
 				} else if( Is304Status( item.WebEx ) ) {
@@ -143,7 +143,7 @@ namespace ClassicalSharp {
 						ExtractDefault();
 					} else if( item.Url != game.World.TextureUrl ) {
 						game.Animations.Dispose();
-						game.ChangeTerrainAtlas( bmp );
+						if( !game.ChangeTerrainAtlas( bmp ) ) { bmp.Dispose(); return; }
 					}
 					
 					if( bmp != null ) game.World.TextureUrl = item.Url;
diff --git a/ClassicalSharp/TexturePack/Animations.cs b/ClassicalSharp/TexturePack/Animations.cs
index 924617c08..b5acea3a0 100644
--- a/ClassicalSharp/TexturePack/Animations.cs
+++ b/ClassicalSharp/TexturePack/Animations.cs
@@ -35,8 +35,8 @@ namespace ClassicalSharp.TexturePack {
 		public void Tick( double delta ) {
 			if( animations.Count == 0 ) return;
 			if( fastBmp == null ) {
-				game.Chat.Add( "&cCurrent texture pack specifies it uses animations,");
-				game.Chat.Add( "&cbut it is missing animations.png");
+				game.Chat.Add( "&cCurrent texture pack specifies it uses animations," );
+				game.Chat.Add( "&cbut is missing animations.png" );
 				animations.Clear();
 				return;
 			}
diff --git a/ClassicalSharp/TexturePack/TexturePackExtractor.cs b/ClassicalSharp/TexturePack/TexturePackExtractor.cs
index e41cffe59..1a708aa69 100644
--- a/ClassicalSharp/TexturePack/TexturePackExtractor.cs
+++ b/ClassicalSharp/TexturePack/TexturePackExtractor.cs
@@ -43,7 +43,9 @@ namespace ClassicalSharp.TexturePack {
 			
 			switch( filename ) {
 				case "terrain.png":
-					game.ChangeTerrainAtlas( Platform.ReadBmp( stream ) ); break;
+					Bitmap atlas = Platform.ReadBmp( stream );
+					if( !game.ChangeTerrainAtlas( atlas ) ) atlas.Dispose();
+					break;
 				case "chicken.png":
 					UpdateTexture( ref cache.ChickenTexId, stream, false ); break;
 				case "creeper.png":