*** empty log message ***

[bpt/emacs.git] / src / abbrev.c

diff --git a/src/abbrev.c b/src/abbrev.c
index e371797..bdb8dc6 100644 (file)
--- a/src/abbrev.c
+++ b/src/abbrev.c
@@ -1,12 +1,12 @@
 /* Primitives for word-abbrev mode.
    Copyright (C) 1985, 1986, 1993, 1996, 1998, 2001, 2002, 2003, 2004,
-                 2005, 2006 Free Software Foundation, Inc.
+                 2005, 2006, 2007 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
 GNU Emacs is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
+the Free Software Foundation; either version 3, or (at your option)
 any later version.
 
 GNU Emacs is distributed in the hope that it will be useful,
@@ -83,7 +83,7 @@ EMACS_INT last_abbrev_point;
 
 Lisp_Object Vpre_abbrev_expand_hook, Qpre_abbrev_expand_hook;
 
-Lisp_Object Qsystem_type, Qcount;
+Lisp_Object Qsystem_type, Qcount, Qforce;
 \f
 DEFUN ("make-abbrev-table", Fmake_abbrev_table, Smake_abbrev_table, 0, 0, 0,
        doc: /* Create a new, empty abbrev table object.  */)
@@ -107,10 +107,10 @@ DEFUN ("clear-abbrev-table", Fclear_abbrev_table, Sclear_abbrev_table, 1, 1, 0,
     XVECTOR (table)->contents[i] = make_number (0);
   return Qnil;
 }
-\f
+
 DEFUN ("define-abbrev", Fdefine_abbrev, Sdefine_abbrev, 3, 6, 0,
        doc: /* Define an abbrev in TABLE named NAME, to expand to EXPANSION and call HOOK.
-NAME must be a string.
+NAME must be a string, and should be lower-case.
 EXPANSION should usually be a string.
 To undefine an abbrev, define it with EXPANSION = nil.
 If HOOK is non-nil, it should be a function of no arguments;
@@ -123,7 +123,9 @@ usage-count, which is incremented each time the abbrev is used.
 \(The default is zero.)
 
 SYSTEM-FLAG, if non-nil, says that this is a "system" abbreviation
-which should not be saved in the user's abbreviation file.  */)
+which should not be saved in the user's abbreviation file.
+Unless SYSTEM-FLAG is `force', a system abbreviation will not
+overwrite a non-system abbreviation of the same name.  */)
      (table, name, expansion, hook, count, system_flag)
      Lisp_Object table, name, expansion, hook, count, system_flag;
 {
@@ -131,6 +133,16 @@ which should not be saved in the user's abbreviation file.  */)
   CHECK_VECTOR (table);
   CHECK_STRING (name);
 
+  /* If defining a system abbrev, do not overwrite a non-system abbrev
+     of the same name, unless 'force is used. */
+  if (!NILP (system_flag) && !EQ (system_flag, Qforce))
+    {
+      sym = Fintern_soft (name, table);
+
+      if (!NILP (SYMBOL_VALUE (sym)) &&
+          NILP (Fplist_get (XSYMBOL (sym)->plist, Qsystem_type))) return Qnil;
+    }
+
   if (NILP (count))
     count = make_number (0);
   else
@@ -640,6 +652,9 @@ syms_of_abbrev ()
   Qcount = intern ("count");
   staticpro (&Qcount);
 
+  Qforce = intern ("force");
+  staticpro (&Qforce);
+
   DEFVAR_LISP ("abbrev-table-name-list", &Vabbrev_table_name_list,
               doc: /* List of symbols whose values are abbrev tables.  */);
   Vabbrev_table_name_list = Fcons (intern ("fundamental-mode-abbrev-table"),
@@ -664,7 +679,7 @@ for any particular abbrev defined in both.  */);
 
   DEFVAR_LISP ("last-abbrev-text", &Vlast_abbrev_text,
               doc: /* The exact text of the last abbrev expanded.
-nil if the abbrev has already been unexpanded.  */);
+A value of nil means the abbrev has already been unexpanded.  */);
 
   DEFVAR_INT ("last-abbrev-location", &last_abbrev_point,
              doc: /* The location of the start of the last abbrev expanded.  */);