Tell the client the LevelChainId before it uses it to read a variable bit length message

scripts/client/nodes/PlanetNode.as

@@ -262,6 +262,19 @@ class DynTex {
 			return;
 		}
 
+		// Try to fail more gracefully than causing a CTD if the
+		// grid size is wrong
+		// If the netcode messes up this can sometimes be way larger than any
+		// actual grid size. In that scenario, trying to create the Image
+		// can easily cause a Crash To Desktop and completely stop the game.
+		if (size.x > 3000 || size.y > 3000) {
+			print("Read grid size that is way too high, aborting texture cache to avoid CTD");
+			print(string(size.x)+"x"+string(size.y));
+			print("Has the netcode or PlanetSurface gone haywire?");
+			@this.obj = null;
+			return;
+		}
+
 		Image img(size, 4);
 
 		uint shown = obj.getSurfaceData(img);

scripts/server/planets/SurfaceComponent.as

@@ -2591,6 +2591,17 @@ tidy class SurfaceComponent : Component_SurfaceComponent, Savable {
 			msg.write0();
 		}
 		msg.writeBit(needsPopulationForLevel);
+		// Tell the client the LevelChainId before it tries to use it, fixes
+		// bug where the client was reading the max level of a planet before
+		// it found out the level chain of that planet. This meant that any
+		// planet with a level chain that had a different max level to the
+		// level chain with an id of 0 would be decoded incorrectly, and offset
+		// the rest of the message by some number of bits, completely breaking
+		// all decoding that followed. In the worst case, the broken decoding
+		// would cause a Crash To Desktop as the PlanetNode tried to create
+		// an Image with a ludicrous size, or the PlanetSurface tried to
+		// create an array for a ludicrous grid size that ran out of memory.
+		msg.writeLimited(LevelChainId,getLevelChainCount());
 		msg.writeLimited(ResourceLevel,maxLevel);
 		msg.writeBit(isSendingColonizers);
 	}

scripts/shadow/planets/SurfaceComponent.as

@@ -435,6 +435,17 @@ tidy class SurfaceComponent : Component_SurfaceComponent {
 			growthRate = 1.0;
 		needsPopulationForLevel = msg.readBit();
 
+		// Tell the client the LevelChainId before it tries to use it, fixes
+		// bug where the client was reading the max level of a planet before
+		// it found out the level chain of that planet. This meant that any
+		// planet with a level chain that had a different max level to the
+		// level chain with an id of 0 would be decoded incorrectly, and offset
+		// the rest of the message by some number of bits, completely breaking
+		// all decoding that followed. In the worst case, the broken decoding
+		// would cause a Crash To Desktop as the PlanetNode tried to create
+		// an Image with a ludicrous size, or the PlanetSurface tried to
+		// create an array for a ludicrous grid size that ran out of memory.
+		LevelChainId = msg.readLimited(getLevelChainCount());
 		int maxLevel = getLevelChain(LevelChainId).levels.length-1;
 		ResourceLevel = msg.readLimited(maxLevel);