Re: rmail-summary-by-thread splits window in two

[Eli Zaretskii]

> From: Andrea Monaco <andrea.monaco@autistici.org>
> Date: Fri, 05 Jan 2024 14:58:48 +0100
> 
> 
> When my emacs has a single window with RMAIL-summary, if I run
> rmail-summary-by-thread then the window gets split horizontally in two
> windows that show identically the result.
> 
> Can someone replicate?  This is harmless, but there's no reason for this
> split, so it seems a little bug.

It's because rmail-summary-by-thread calls rmail-new-summary with the
rmail-buffer the current buffer.  The patch below seems to fix that,
does it look like the right fix?

diff --git a/lisp/mail/rmailsum.el b/lisp/mail/rmailsum.el
index 30fe75f..cccd702 100644
--- a/lisp/mail/rmailsum.el
+++ b/lisp/mail/rmailsum.el
@@ -436,19 +436,19 @@ rmail-summary-by-thread
     (unless (and rmail-summary-message-parents-vector
                 (= (length rmail-summary-message-parents-vector)
                    (1+ rmail-total-messages)))
-      (rmail-summary-fill-message-parents-and-descs-vectors))
-    (let ((enc-msgs (make-bool-vector (1+ rmail-total-messages) nil)))
-      (rmail-summary--walk-thread-message-recursively msgnum enc-msgs)
-      (rmail-new-summary (format "thread containing message %d" msgnum)
-                        (list 'rmail-summary-by-thread msgnum)
-                        (if (and rmail-summary-progressively-narrow
-                                 (rmail-summary--exists-1))
-                            (lambda (msg _msgnum)
-                              (and (aref 
rmail-summary-currently-displayed-msgs msg)
-                                   (aref enc-msgs msg)))
+      (rmail-summary-fill-message-parents-and-descs-vectors)))
+  (let ((enc-msgs (make-bool-vector (1+ rmail-total-messages) nil)))
+    (rmail-summary--walk-thread-message-recursively msgnum enc-msgs)
+    (rmail-new-summary (format "thread containing message %d" msgnum)
+                      (list 'rmail-summary-by-thread msgnum)
+                      (if (and rmail-summary-progressively-narrow
+                               (rmail-summary--exists-1))
                           (lambda (msg _msgnum)
-                             (aref enc-msgs msg)))
-                        msgnum))))
+                            (and (aref rmail-summary-currently-displayed-msgs 
msg)
+                                 (aref enc-msgs msg)))
+                        (lambda (msg _msgnum)
+                           (aref enc-msgs msg)))
+                      msgnum)))
 
 ;;;###autoload
 (defun rmail-summary-by-labels (labels)