master 88c9696: Fix compact mode line text properties

[Lars Ingebrigtsen]

branch: master
commit 88c96962cfd56f213ef88b506b510a42d21a2fe6
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Fix compact mode line text properties
    
    * src/xdisp.c (display_mode_line): Display the compact mode
    correctly (with text properties) (bug#45520).
---
 src/xdisp.c | 41 +++++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/src/xdisp.c b/src/xdisp.c
index f7b87dc..4c4d349 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -25473,30 +25473,43 @@ display_mode_line (struct window *w, enum face_id 
face_id, Lisp_Object format)
          && window_body_width (XWINDOW (selected_window), FALSE) >=
          SCHARS (mode_string))
        {
+         /* The window is wide enough; just display the mode line we
+            just computed. */
          display_string (SSDATA (mode_string), mode_string, Qnil,
                          0, 0, &it, 0, 0, 0,
                          STRING_MULTIBYTE (mode_string), FALSE);
        }
       else
        {
-         char *string = xmalloc (SBYTES (mode_string) + 1),
-           *ostring = SSDATA (mode_string);
-         char *s = string, prev = 0;
+         /* Compress the mode line. */
+         ptrdiff_t i = 0, i_byte = 0, start = 0;
+         int prev = 0;
 
-         /* Copy over the data from the mode line string, but ignore
-            repeating spaces.  This should be safe even for multibyte
-            strings, since this is UTF-8. */
-         for (int i = 0; i < SBYTES (mode_string); i++)
+         while (i < SCHARS (mode_string))
            {
-             char c = ostring[i];
-             if (!(c == ' ' && prev == ' '))
-               prev = *s++ = c;
+             int c = fetch_string_char_advance (mode_string, &i, &i_byte);
+             if (c == ' ' && prev == ' ')
+               {
+                 display_string (NULL,
+                                 Fsubstring (mode_string, make_fixnum (start),
+                                             make_fixnum (i - 1)),
+                                 Qnil, 0, 0, &it, 0, 0, 0,
+                                 STRING_MULTIBYTE (mode_string), FALSE);
+                 /* Skip past the rest of the space characters. */
+                 while (c == ' ' && i < SCHARS (mode_string))
+                     c = fetch_string_char_advance (mode_string, &i, &i_byte);
+                 start = i - 1;
+               }
+             prev = c;
            }
-         *s = 0;
 
-         display_string (string, Qnil, Qnil, 0, 0, &it, 0, 0, 0,
-                         STRING_MULTIBYTE (mode_string), TRUE);
-         xfree (string);
+         /* Display the final bit. */
+         if (start < i)
+           display_string (NULL,
+                           Fsubstring (mode_string, make_fixnum (start),
+                                       make_fixnum (i - 1)),
+                           Qnil, 0, 0, &it, 0, 0, 0,
+                           STRING_MULTIBYTE (mode_string), FALSE);
        }
     }
   pop_kboard ();