Hi, I have been enjoying using Emacs since more than 20 years now. So, thank you all guys for this impressive work. It is the first time I send a patch to this list. I am not a very fluent lisp coder so please do apologies if the style is not very good and feel free to tell me how to improve it. Currently, `split-window-sensibly' prefers to split vertically, disregarding the shape of the frame. This is a good default when Emacs is taller than wider. However, when Emacs is in fullscreen (landscape screen layout), splitting vertically is generally not the thing to do because there is plenty of space on the right. Typical scenario: Emacs is in fullscreen; one buffer is open in a window covering the entire frame. Another buffer is opened in a second window (C-x 4 f). In this case, the split should generally be horizontal. The attached patch changes `split-window-sensibly' to just try spliting the longest edge first. It works well when implemented in my init.el and installed by setting `split-window-preferred-function'. However, when the same logic is implemented by directly modifying `split-window-sensibly' in window.el, it does not work for one very specific case: when the frame is 80x30 and C-x 4 f is pressed, the window is not split and the buffer is opened in another frame. The problem seems to come from the last eval expression at the bottom of `split-window-sensibly', but I failed to find a solution. I though better elisp coder than me will find a solution quickly that's why I am posting here. Apart from that, I have been using this alternate approach for a couple of weeks now, and it works well, that's why I am submitting it for inclusion in Emacs. I have tested on 8d94a9ec613470b7e8e4ee0e86b643f34f8a724c with emacs built with --with-imagemagick --with-native-compilation=yes --with-compress-install --with-mailutils --with-gnutls --with-tree-sitter --with-xwidgets --disable-gc-mark-trace --no-create --no-recursion on macOS 15.2. Best regards, Nico -- Nicolas Desprès