Fix bug #14408 with updating *Messages* display.

 src/xdisp.c (message_dolog): If the *Messages* buffer is shown in
 some window, increment windows_or_buffers_changed, so that
 *Messages* display in that window is updated.

2 files changed, 13 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index e5308e2db3b..42b21abc8ae 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2013-05-16  Eli Zaretskii  <eliz@gnu.org>
 
+        * xdisp.c (message_dolog): If the *Messages* buffer is shown in
+        some window, increment windows_or_buffers_changed, so that
+        *Messages* display in that window is updated.  (Bug#14408)
+
         * w32.c: Include epaths.h.
         (init_environment): Use cmdproxy.exe without leading directories.
         Support emacs.exe in src; point SHELL to cmdproxy in ../nt in that
diff --git a/src/xdisp.c b/src/xdisp.c
index 0a79e6fd891..3f7e8610a09 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -9537,7 +9537,15 @@ message_dolog (const char *m, ptrdiff_t nbytes, bool nlflag, bool multibyte)
 
       shown = buffer_window_count (current_buffer) > 0;
       set_buffer_internal (oldbuf);
-      if (!shown)
+      /* We called insert_1_both above with its 5th argument (PREPARE)
+         zero, which prevents insert_1_both from calling
+         prepare_to_modify_buffer, which in turns prevents us from
+         incrementing windows_or_buffers_changed even if *Messages* is
+         shown in some window.  So we must manually incrementing
+         windows_or_buffers_changed here to make up for that.  */
+      if (shown)
+        windows_or_buffers_changed++;
+      else
         windows_or_buffers_changed = old_windows_or_buffers_changed;
       message_log_need_newline = !nlflag;
       Vdeactivate_mark = old_deactivate_mark;