Avoid character to byte conversions in motion subroutines.

* indent.h (compute_motion, vmotion): Add byte position argument.
* indent.c (compute_motion): Use it and avoid CHAR_TO_BYTE.
Add eassert.
(Fcompute_motion): Break long line.  Adjust call to compute_motion.
Use list5 for return value.
(vmotion): Use byte position argument and avoid call to CHAR_TO_BYTE.
Adjust comments, style and calls to compute_motion.
(Fvertical_motion): Adjust call to vmotion.
* window.c (Fdelete_other_windows_internal): Record window start
byte position and adjust call to vmotion.
(window_scroll_line_based): Likewise with call to compute_motion.
Use SET_PT_BOTH.
(Frecenter): Adjust calls to vmotion.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/indent.h b/src/indent.h
index acfd952754e..4eb3fed6a11 100644
--- a/src/indent.h
+++ b/src/indent.h
@@ -26,14 +26,14 @@ struct position
     int contin;
   };
 
-struct position *compute_motion (ptrdiff_t from, EMACS_INT fromvpos,
-                                 EMACS_INT fromhpos, bool did_motion,
-                                 ptrdiff_t to, EMACS_INT tovpos,
-                                 EMACS_INT tohpos,
+struct position *compute_motion (ptrdiff_t from, ptrdiff_t frombyte,
+				 EMACS_INT fromvpos, EMACS_INT fromhpos,
+				 bool did_motion, ptrdiff_t to,
+				 EMACS_INT tovpos, EMACS_INT tohpos,
                                  EMACS_INT width, ptrdiff_t hscroll,
                                  int tab_offset, struct window *);
-struct position *vmotion (ptrdiff_t from, EMACS_INT vtarget,
-                          struct window *);
+struct position *vmotion (ptrdiff_t from, ptrdiff_t from_byte,
+			  EMACS_INT vtarget, struct window *);
 ptrdiff_t skip_invisible (ptrdiff_t pos, ptrdiff_t *next_boundary_p,
                           ptrdiff_t to, Lisp_Object window);