Subject: Re: bug#62592: Not creating new Tabs with small window

From: Juri Linkov <[email-masked]>
Date: Sun, 02 Apr 2023 20:49:09 +0300

>> 1. ~ $ emacs -Q
>> 2. Menu -> Options -> Show/Hide -> Tab Bar (gives Tab*scratch*)
>> 3. resize the Emacs window to a small one, but large enough to show some Tab labels
>> 3. 1x click on rightmost * in the Tab Bar to create a new Tab
>>
>> The bug: No new Tab will be created and the minibuf and*Messages*  show:
>>
>>    split-window: Window #<window 3 on*Messages*> too small for splitting
>
> Thanks for the bug report.  It is related to bug#62427 where
> we need to find a way to create a new window without using
> delete-windows and split-window.

Oh, I noticed the same problem in window-state-put too :-(
Restoring window states fails with the same error in narrow windows.
However, here is a fix.  Eli, is it ok to fix this in emacs-29?

diff --git a/lisp/tab-bar.el b/lisp/tab-bar.el
index 35474e1c674..08f904ec73d 100644
--- a/lisp/tab-bar.el
+++ b/lisp/tab-bar.el
@@ -1586,7 +1595,8 @@ tab-bar-new-tab-to
               (window-state-put (window-state-get))
             ;; Create a new window to get rid of old window parameters
             ;; (e.g. prev/next buffers) of old window.
-            (split-window) (delete-window))))
+            (let ((window-min-height 1)) (split-window))
+            (delete-window))))
 
       (let ((buffer
              (if (and (functionp tab-bar-new-tab-choice)
diff --git a/lisp/window.el b/lisp/window.el
index aa7520f30fa..b2ee869940a 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -6391,7 +6396,8 @@ window-state-put
                      (selected-window)))
       (delete-other-windows-internal window root)
       ;; Create a new window to replace the existing one.
-      (setq window (prog1 (split-window window)
+      (setq window (prog1 (let ((window-min-height 1))
+                            (split-window window))
                      (delete-window window)))))
 
   (set-window-dedicated-p window nil)