[Emacs-diffs] trunk r118120: Avoid unwanted point motion in Fline_beginning_position.

[Dmitry Antipov]

------------------------------------------------------------
revno: 118120
revision-id: address@hidden
parent: address@hidden
committer: Dmitry Antipov <address@hidden>
branch nick: trunk
timestamp: Wed 2014-10-15 17:37:10 +0400
message:
  Avoid unwanted point motion in Fline_beginning_position.
  * lisp.h (scan_newline_from_point): Add prototype.
  * search.c (scan_newline_from_point): New function, refactored from...
  * cmds.c (Fforward_line): ...adjusted user.
  * editfns.c (Fline_beginning_position): Use scan_newline_from_point
  and simplify the former since the latter doesn't move point.
modified:
  src/ChangeLog                  changelog-20091113204419-o5vbwnq5f7feedwu-1438
  src/cmds.c                     cmds.c-20091113204419-o5vbwnq5f7feedwu-214
  src/editfns.c                  editfns.c-20091113204419-o5vbwnq5f7feedwu-255
  src/lisp.h                     lisp.h-20091113204419-o5vbwnq5f7feedwu-253
  src/search.c                   search.c-20091113204419-o5vbwnq5f7feedwu-473

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2014-10-14 12:45:41 +0000
+++ b/src/ChangeLog     2014-10-15 13:37:10 +0000
@@ -1,3 +1,12 @@
+2014-10-15  Dmitry Antipov  <address@hidden>
+
+       Avoid unwanted point motion in Fline_beginning_position.
+       * lisp.h (scan_newline_from_point): Add prototype.
+       * search.c (scan_newline_from_point): New function, refactored from...
+       * cmds.c (Fforward_line): ...adjusted user.
+       * editfns.c (Fline_beginning_position): Use scan_newline_from_point
+       and simplify the former since the latter doesn't move point.
+
 2014-10-14  Dmitry Antipov  <address@hidden>
 
        Cleanup terminal handling code.

=== modified file 'src/cmds.c'
--- a/src/cmds.c        2014-06-23 04:11:29 +0000
+++ b/src/cmds.c        2014-10-15 13:37:10 +0000
@@ -131,12 +131,7 @@
       count = XINT (n);
     }
 
-  if (count <= 0)
-    pos = find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, count - 1,
-                       &shortage, &pos_byte, 1);
-  else
-    pos = find_newline (PT, PT_BYTE, ZV, ZV_BYTE, count,
-                       &shortage, &pos_byte, 1);
+  shortage = scan_newline_from_point (count, &pos, &pos_byte);
 
   SET_PT_BOTH (pos, pos_byte);
 

=== modified file 'src/editfns.c'
--- a/src/editfns.c     2014-10-12 20:36:49 +0000
+++ b/src/editfns.c     2014-10-15 13:37:10 +0000
@@ -787,26 +787,17 @@
 This function does not move point.  */)
   (Lisp_Object n)
 {
-  ptrdiff_t orig, orig_byte, end;
-  ptrdiff_t count = SPECPDL_INDEX ();
-  specbind (Qinhibit_point_motion_hooks, Qt);
+  ptrdiff_t charpos, bytepos;
 
   if (NILP (n))
     XSETFASTINT (n, 1);
   else
     CHECK_NUMBER (n);
 
-  orig = PT;
-  orig_byte = PT_BYTE;
-  Fforward_line (make_number (XINT (n) - 1));
-  end = PT;
-
-  SET_PT_BOTH (orig, orig_byte);
-
-  unbind_to (count, Qnil);
+  scan_newline_from_point (XINT (n) - 1, &charpos, &bytepos);
 
   /* Return END constrained to the current input field.  */
-  return Fconstrain_to_field (make_number (end), make_number (orig),
+  return Fconstrain_to_field (make_number (charpos), make_number (PT),
                              XINT (n) != 1 ? Qt : Qnil,
                              Qt, Qnil);
 }

=== modified file 'src/lisp.h'
--- a/src/lisp.h        2014-10-12 06:09:50 +0000
+++ b/src/lisp.h        2014-10-15 13:37:10 +0000
@@ -4066,6 +4066,7 @@
                               ptrdiff_t, ptrdiff_t *, ptrdiff_t *, bool);
 extern ptrdiff_t scan_newline (ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t,
                               ptrdiff_t, bool);
+extern ptrdiff_t scan_newline_from_point (ptrdiff_t, ptrdiff_t *, ptrdiff_t *);
 extern ptrdiff_t find_newline_no_quit (ptrdiff_t, ptrdiff_t,
                                       ptrdiff_t, ptrdiff_t *);
 extern ptrdiff_t find_before_next_newline (ptrdiff_t, ptrdiff_t,

=== modified file 'src/search.c'
--- a/src/search.c      2014-09-07 07:04:01 +0000
+++ b/src/search.c      2014-10-15 13:37:10 +0000
@@ -985,6 +985,24 @@
   return shortage;
 }
 
+/* Like above, but always scan from point and report the
+   resulting position in *CHARPOS and *BYTEPOS.  */
+
+ptrdiff_t
+scan_newline_from_point (ptrdiff_t count, ptrdiff_t *charpos,
+                        ptrdiff_t *bytepos)
+{
+  ptrdiff_t shortage;
+
+  if (count <= 0)
+    *charpos = find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, count - 1,
+                            &shortage, bytepos, 1);
+  else
+    *charpos = find_newline (PT, PT_BYTE, ZV, ZV_BYTE, count,
+                            &shortage, bytepos, 1);
+  return shortage;
+}
+
 /* Like find_newline, but doesn't allow QUITting and doesn't return
    SHORTAGE.  */
 ptrdiff_t