frame_internal_border_part 1714 src/frame.h    extern enum internal_border_part frame_internal_border_part (struct frame *f, int x, int y);
frame_internal_border_part 5687 src/keyboard.c 	    = frame_internal_border_part (f, xret, yret);
frame_internal_border_part 35158 src/xdisp.c          enum internal_border_part part = frame_internal_border_part (f, x, y);