bug#7307: 24.0.50; Mode line had more than just dashes removed

[Stephen Berman]

On Sat, 30 Oct 2010 08:51:14 +0200 Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Stephen Berman <stephen.berman@gmx.net>
>> Date: Sat, 30 Oct 2010 01:05:32 +0200
>> Cc: 
>> 
>> The only problem is specifying the length of the
>> string: (window-width) as the maximum possible length fails here,
>> because the mode line is constructed before the window-system frame, and
>> has a value of just 10.  So I just picked 200 as a plausible maximum.
>> Maybe there's a better way, but this seems to work ok.
>
> Would it help to use window-width as the maximum?

?? See above.  Or did you mean something else?  (Though I see that what
I wrote is a bit garbled: it should say "(window-width) has a value of
just 10".)  Anyway, maybe it's less kludgy to introduce a mode line
%-construct for spaces.  Here's a patch for that, which just adapts the
code for "%-".  It seems to works (but so does my other lisp-only
patch).  (Interestingly, lots_of_dashes, and hence lots_of_spaces, has a
length of 140, but that's enough at least for my screen.)

=== modified file 'doc/lispref/modes.texi'
--- doc/lispref/modes.texi      2010-08-22 19:30:26 +0000
+++ doc/lispref/modes.texi      2010-10-30 13:01:23 +0000
@@ -2029,6 +2029,9 @@
 @item %-
 Dashes sufficient to fill the remainder of the mode line.
 
+@item %_
+Spaces sufficient to fill the remainder of the mode line.
+
 @item %%
 The character @samp{%}---this is how to include a literal @samp{%} in a
 string in which @code{%}-constructs are allowed.

=== modified file 'lisp/bindings.el'
--- lisp/bindings.el    2010-10-19 19:20:33 +0000
+++ lisp/bindings.el    2010-10-30 13:01:56 +0000
@@ -336,7 +336,8 @@
         'mode-line-modes
         `(which-func-mode ("" which-func-format ,spaces))
         `(global-mode-string ("" global-mode-string ,spaces))
-        `(:eval (unless (display-graphic-p)
+        `(:eval (if (display-graphic-p)
+                    ,(propertize " %_" 'help-echo help-echo)
                   ,(propertize "-%-" 'help-echo help-echo)))))
        (standard-mode-line-modes
        (list

=== modified file 'src/buffer.c'
--- src/buffer.c        2010-10-29 03:29:29 +0000
+++ src/buffer.c        2010-10-30 13:01:37 +0000
@@ -5571,6 +5571,7 @@
         remote machine.
   %[ -- print one [ for each recursive editing level.  %] similar.
   %% -- print %.   %- -- print infinitely many dashes.
+  %_ -- print infinitely many spaces.
 Decimal digits after the % specify field width to which to pad.  */);
 
   DEFVAR_LISP_NOPRO ("default-major-mode", &buffer_defaults.major_mode,

=== modified file 'src/xdisp.c'
--- src/xdisp.c 2010-10-23 21:19:02 +0000
+++ src/xdisp.c 2010-10-30 12:37:24 +0000
@@ -19269,6 +19269,8 @@
 
 static char lots_of_dashes[] = 
"--------------------------------------------------------------------------------------------------------------------------------------------";
 
+static char lots_of_spaces[] = "                                               
                                                                                
             ";
+
 static const char *
 decode_mode_spec (struct window *w, register int c, int field_width,
                  int precision, Lisp_Object *string)
@@ -19355,6 +19357,26 @@
          return lots_of_dashes;
       }
 
+    case '_':
+      {
+       register int i;
+
+       /* Let lots_of_spaces be a string of infinite length.  */
+       if (mode_line_target == MODE_LINE_NOPROP ||
+           mode_line_target == MODE_LINE_STRING)
+         return "  ";
+       if (field_width <= 0
+           || field_width > sizeof (lots_of_spaces))
+         {
+           for (i = 0; i < FRAME_MESSAGE_BUF_SIZE (f) - 1; ++i)
+             decode_mode_spec_buf[i] = ' ';
+           decode_mode_spec_buf[i] = '\0';
+           return decode_mode_spec_buf;
+         }
+       else
+         return lots_of_dashes;
+      }
+
     case 'b':
       obj = b->name;
       break;