internal_border_part 2468 src/frame.c    enum internal_border_part
internal_border_part 2475 src/frame.c      enum internal_border_part part = INTERNAL_BORDER_NONE;
internal_border_part 1714 src/frame.h    extern enum internal_border_part frame_internal_border_part (struct frame *f, int x, int y);
internal_border_part 5686 src/keyboard.c 	  enum internal_border_part part
internal_border_part 35158 src/xdisp.c          enum internal_border_part part = frame_internal_border_part (f, x, y);