Re: removing duplicate from history by default

[Dan Nicolaescu]

Juri Linkov <address@hidden> writes:

  > Richard Stallman <address@hidden> writes:
>>     Let's reopen the discussion started with the message here:
>>
>>     http://lists.gnu.org/archive/html/emacs-devel/2004-06/msg00021.html
>>
>> No, please let's not.  What we need to do now is fix the problems
>> that prevent a release.  Please let's not take up other changes
>> which are not necessary now.
>
  > Concentrating on making the next release is undoubtedly the top priority,
  > but the proposed change is so small (but still very useful), that it's
  > better to install it now than to raise the same question again in the futur\
e.

Agreed, the code changes are minimal: 1 line of code added + glue code
to declare a lisp variable. Plus the code already exists, I have used
it for a few months with no problems.

  > Dan Nicolaescu <address@hidden> writes:
>
>> There was one question left, if removing duplicates from history
>> should be turned on by default.
>
  > Let's not turn it on by default.  Even shells don't set a variable to
  > remove duplicates by default, isn't?  

Right. 

  > And so this change will not change the current Emacs behavior.

Sure, a complete patch is attached. Please install it if it's OK. 

2004-09-05  Dan Nicolaescu  <address@hidden>

        * minibuf.c (history_delete_duplicates): New variable.
        (read_minibuf): Use it.
        (syms_of_minibuf): Create the corresponding lisp variable.


Index: NEWS
===================================================================
RCS file: /cvsroot/emacs/emacs/etc/NEWS,v
retrieving revision 1.1019
diff -c -3 -p -c -r1.1019 NEWS
*** NEWS        2 Sep 2004 16:39:19 -0000       1.1019
--- NEWS        5 Sep 2004 17:54:45 -0000
*************** from the file name or buffer contents.
*** 1792,1797 ****
--- 1798,1807 ----
  This option can be disabled, to avoid the normal behavior of isearch
  which puts calls to `isearch-resume' in the command history.
  
+ ** New user option `history-delete-duplicate'.
+ If set to t when adding a new history entry, all previous identical
+ entries are deleted. 
+ 
  ---
  ** Lisp mode now uses font-lock-doc-face for the docstrings.
  

Index: minibuf.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/minibuf.c,v
retrieving revision 1.271
diff -c -3 -p -c -r1.271 minibuf.c
*** minibuf.c   14 Aug 2004 12:46:46 -0000      1.271
--- minibuf.c   5 Sep 2004 17:40:26 -0000
*************** Lisp_Object Vcompletion_auto_help;
*** 61,66 ****
--- 61,71 ----
  
  Lisp_Object Qhistory_length, Vhistory_length;
  
+ /* No duplicates in history.  */
+ 
+ int history_delete_duplicates;
+ 
+ 
  /* Fread_minibuffer leaves the input here as a string. */
  
  Lisp_Object last_minibuf_string;
*************** read_minibuf (map, initial, prompt, back
*** 749,755 ****
        {
          Lisp_Object length;
  
!         histval = Fcons (histstring, histval);
          Fset (Vminibuffer_history_variable, histval);
  
          /* Truncate if requested.  */
--- 754,761 ----
        {
          Lisp_Object length;
  
!         if (history_delete_duplicates) Fdelete (histstring, histval);
!           histval = Fcons (histstring, histval);
          Fset (Vminibuffer_history_variable, histval);
  
          /* Truncate if requested.  */
*************** just after a new element is inserted.  S
*** 2668,2673 ****
--- 2674,2685 ----
  property of a history variable overrides this default.  */);
    XSETFASTINT (Vhistory_length, 30);
  
+   DEFVAR_BOOL ("history-delete-duplicates", &history_delete_duplicates,
+              doc: /* *Non-nil means delete duplicates in history.
+ If set to t when adding a new history entry, all previous identical
+ entries are deleted.  */);
+   history_delete_duplicates = 0;
+   
    DEFVAR_LISP ("completion-auto-help", &Vcompletion_auto_help,
               doc: /* *Non-nil means automatically provide help for invalid 
completion input.  */);
    Vcompletion_auto_help = Qt;