Fix python error in image sampling panel drawing when

there is no texture slot available.

release/scripts/startup/bl_ui/properties_texture.py

@@ -393,7 +393,7 @@ class TEXTURE_PT_image_sampling(TextureTypePanel, bpy.types.Panel):
 
         idblock = context_tex_datablock(context)
         tex = context.texture
-        slot = context.texture_slot
+        slot = getattr(context, "texture_slot", None)
 
         split = layout.split()
 
@@ -408,7 +408,7 @@ class TEXTURE_PT_image_sampling(TextureTypePanel, bpy.types.Panel):
         col = split.column()
 
         #Only for Material based textures, not for Lamp/World...
-        if isinstance(idblock, bpy.types.Material):
+        if slot and isinstance(idblock, bpy.types.Material):
             col.prop(tex, "use_normal_map")
             row = col.row()
             row.active = tex.use_normal_map