field-beginning ignores ESCAPE-FROM-EDGE

[Lars Hansen]

field-beginning ignores ESCAPE-FROM-EDGE when POS is at a field
beginning. The attached patch fixes the bug and corrects the description
(comment) of find_field.
If there are no objections, I will install in about a week.

*** editfns.c.~1.412.~  2006-04-11 23:32:35.000000000 +0200
--- editfns.c   2006-04-14 16:41:37.000000000 +0200
***************
*** 491,514 ****
  }
  
  /* Find the field surrounding POS in *BEG and *END.  If POS is nil,
!    the value of point is used instead.  If BEG or END null,
     means don't store the beginning or end of the field.
  
     BEG_LIMIT and END_LIMIT serve to limit the ranged of the returned
     results; they do not effect boundary behavior.
  
!    If MERGE_AT_BOUNDARY is nonzero, then if POS is at the very first
!    position of a field, then the beginning of the previous field is
!    returned instead of the beginning of POS's field (since the end of a
!    field is actually also the beginning of the next input field, this
!    behavior is sometimes useful).  Additionally in the MERGE_AT_BOUNDARY
     true case, if two fields are separated by a field with the special
     value `boundary', and POS lies within it, then the two separated
     fields are considered to be adjacent, and POS between them, when
!    finding the beginning and ending of the "merged" field.
! 
!    Either BEG or END may be 0, in which case the corresponding value
!    is not stored.  */
  
  static void
  find_field (pos, merge_at_boundary, beg_limit, beg, end_limit, end)
--- 491,511 ----
  }
  
  /* Find the field surrounding POS in *BEG and *END.  If POS is nil,
!    the value of point is used instead.  If BEG or END is null,
     means don't store the beginning or end of the field.
  
     BEG_LIMIT and END_LIMIT serve to limit the ranged of the returned
     results; they do not effect boundary behavior.
  
!    If MERGE_AT_BOUNDARY is nonzero, then if POS is at the very last
!    position of a field, then the end of the next field is returned
!    instead of the end of POS's field (since the end of a field is
!    actually also the beginning of the next input field, this behavior
!    is sometimes useful).  Additionally in the MERGE_AT_BOUNDARY
     true case, if two fields are separated by a field with the special
     value `boundary', and POS lies within it, then the two separated
     fields are considered to be adjacent, and POS between them, when
!    finding the beginning and ending of the "merged" field.  */
  
  static void
  find_field (pos, merge_at_boundary, beg_limit, beg, end_limit, end)
***************
*** 674,682 ****
       (pos, escape_from_edge, limit)
       Lisp_Object pos, escape_from_edge, limit;
  {
!   int beg;
!   find_field (pos, escape_from_edge, limit, &beg, Qnil, 0);
!   return make_number (beg);
  }
  
  DEFUN ("field-end", Ffield_end, Sfield_end, 0, 3, 0,
--- 671,681 ----
       (pos, escape_from_edge, limit)
       Lisp_Object pos, escape_from_edge, limit;
  {
!   int beg, end;
!   find_field (pos, escape_from_edge, limit, &beg, Qnil, &end);
!   return make_number (NILP (escape_from_edge)
!                       && XFASTINT (pos) == end
!                       && end != ZV ? end : beg);
  }
  
  DEFUN ("field-end", Ffield_end, Sfield_end, 0, 3, 0,