void reset_gutter_display_lines (struct frame* f);
void gutter_extent_signal_changed_region_maybe (Lisp_Object obj,
Bufpos start, Bufpos end);
+int display_boxes_in_gutter_p (struct frame *f, struct display_box* db,
+ struct display_glyph_area* dga);
#define WINDOW_GUTTER_BORDER_WIDTH(w, pos) \
(INTP ((w)->gutter_border_width[pos]) ? XINT ((w)->gutter_border_width[pos]) : 0)