Empty var call in css crashes GTK
writing
button {
--accent-fg-color: var();
}
on style.css on a libadwaita app with a GtkButton (the only relevant part is for the variable to do something on a widget that is currently displayed) will crash the app with error:
Gtk:ERROR:../gtk/css/gtkcssparser.c:429:gtk_css_parser_ensure_token: assertion failed: (gtk_css_parser_has_token (self, GTK_CSS_TOKEN_IDENT))
Bail out! Gtk:ERROR:../gtk/css/gtkcssparser.c:429:gtk_css_parser_ensure_token: assertion failed: (gtk_css_parser_has_token (self, GTK_CSS_TOKEN_IDENT))
Application exited
While this is clearly invalid CSS, it is easy to run into this situation while using the inspector and a crash is unexpected in this case.
cc @alicem