bugfix after onContextLost

hxd/impl/CacheAllocator.hx

@@ -64,6 +64,7 @@ class CacheAllocator extends Allocator {
 	}
 
 	override function disposeBuffer(b:h3d.Buffer) {
+		if( b.isDisposed() ) return;
 		var f = b.flags;
 		var flags = f.has(RawFormat) ? (f.has(Quads) ? RawQuads : RawFormat) : (f.has(UniformBuffer) ? UniformDynamic : Dynamic);
 		var id = flags.toInt() | (b.buffer.stride << 3) | (b.vertices << 16);
@@ -89,6 +90,7 @@ class CacheAllocator extends Allocator {
 	}
 
 	override function disposeIndexBuffer( i : h3d.Indexes ) {
+		if( i.isDisposed() ) return;
 		var id = i.count;
 		var c = indexBuffers.get(id);
 		if( c == null ) {