- added valid texture image check to draw_primitive_begin_texture

Author: JonnoRobson

scripts/Builders/yyPrimBuilder.js

@@ -133,6 +133,10 @@ function WebGL_draw_primitive_begin_texture_RELEASE(_kind, _tex) {
     // If they've managed to find a path through the code without this texture being bound...
     if (g_PrimTexture && !g_PrimTexture.webgl_textureid) {
         WebGL_BindTexture({texture: g_PrimTexture});
+		if(WebGL_IsTextureImageValid(g_PrimTexture.webgl_textureid)) {
+            yyError("draw_primitive_begin_texture: trying to use an invalid texture");
+			return;
+		}
     }
 
     g_PrimVBuffer = new yyVBuffer(DEFAULT_VB_SIZE, g_webGL.GetVertexFormat(g_webGL.VERTEX_FORMAT_2D), false);