Non-UTF encoded strings causes coloring offset when using clang model

I'm working on C89 project with files encoded in ISO-8859-2. When I'm having a string containing raw 8-bit characters, code following that string has its syntax coloring offset by the amount of 8-bit chars in that string until line end.

After reopening the file, syntax coloring matches code as it should unill I edit anywhere in that file, then it breaks as before.

Built-in qtc code model works ok.
Passing „-finput-charset=iso-8859-2” to clang model in project settings has no effect

Attachments:

• color_offset_latin2.png → broken syntax coloring, encoding: ISO-8859-2
• color_offset_utf8.png → after switching file encoding to UTF-8
• color_offset_latin2_ok.png → coloring is ok after reloading the file, encoding ISO-8859-2