From 9492df027d0715e2bbd3508d6733fd6f6ca6de0b Mon Sep 17 00:00:00 2001
From: Rahul Yedida <yrahul3910@gmail.com>
Date: Wed, 18 Feb 2026 01:57:59 -0500
Subject: [PATCH] fix(defaults): 'guifont' "monospace" fallback, trim spaces
 #37930

Problem:
Some UI clients break if space follows the comma in 'guifont' items.
Also the new 'guifont' default may cause problems if none of the fonts are found.

Solution:
Remove trailing whitespace.
Add a "monospace" fallback which `fontconfig` can resolve on *nix systems.
---
 runtime/doc/options.txt           | 5 ++++-
 runtime/lua/vim/_meta/options.lua | 2 +-
 src/nvim/option_vars.h            | 8 ++++----
 src/nvim/options.lua              | 4 ++++
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 6e5e896a18..8a877a8c7c 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3344,7 +3344,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 <
 
 					*'guifont'* *'gfn'* *E235* *E596*
-'guifont' 'gfn'		string	(default "Source Code Pro, DejaVu Sans Mono, Courier New")
+'guifont' 'gfn'		string	(default (MS-Windows) "Cascadia Code,Cascadia Mono,Consolas,Courier New,monospace"
+                                            (Mac) "SF Mono,Menlo,Monaco,Courier New,monospace"
+                                          (Linux) "Source Code Pro,DejaVu Sans Mono,Courier New,monospace"
+                                         (others) "DejaVu Sans Mono,Courier New,monospace")
 			global
 	This is a list of fonts which will be used for the GUI version of Vim.
 	In its simplest form the value is just one font name.  When
diff --git a/runtime/lua/vim/_meta/options.lua b/runtime/lua/vim/_meta/options.lua
index fda617d610..81fb7e09ff 100644
--- a/runtime/lua/vim/_meta/options.lua
+++ b/runtime/lua/vim/_meta/options.lua
@@ -3237,7 +3237,7 @@ vim.go.gcr = vim.go.guicursor
 ---
 ---
 --- @type string
-vim.o.guifont = "Source Code Pro, DejaVu Sans Mono, Courier New"
+vim.o.guifont = "Source Code Pro,DejaVu Sans Mono,Courier New,monospace"
 vim.o.gfn = vim.o.guifont
 vim.go.guifont = vim.o.guifont
 vim.go.gfn = vim.go.guifont
diff --git a/src/nvim/option_vars.h b/src/nvim/option_vars.h
index a3ad2446f3..a8f26f4730 100644
--- a/src/nvim/option_vars.h
+++ b/src/nvim/option_vars.h
@@ -34,13 +34,13 @@
 
 // Default values for 'guifont'
 #ifdef MSWIN
-# define DFLT_GFN "Cascadia Code, Cascadia Mono, Consolas, Courier New"
+# define DFLT_GFN "Cascadia Code,Cascadia Mono,Consolas,Courier New,monospace"
 #elif defined(__APPLE__)
-# define DFLT_GFN "SF Mono, Menlo, Monaco, Courier New"
+# define DFLT_GFN "SF Mono,Menlo,Monaco,Courier New,monospace"
 #elif defined(__linux__)
-# define DFLT_GFN "Source Code Pro, DejaVu Sans Mono, Courier New"
+# define DFLT_GFN "Source Code Pro,DejaVu Sans Mono,Courier New,monospace"
 #else
-# define DFLT_GFN "DejaVu Sans Mono, Courier New"
+# define DFLT_GFN "DejaVu Sans Mono,Courier New,monospace"
 #endif
 
 #define DFLT_GREPFORMAT "%f:%l:%m,%f:%l%m,%f  %l%m"
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index 832d6ea4fd..ebc613d810 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -3998,6 +3998,10 @@ local options = {
       abbreviation = 'gfn',
       defaults = {
         if_true = macros('DFLT_GFN', 'string'),
+        doc = [[(MS-Windows) "Cascadia Code,Cascadia Mono,Consolas,Courier New,monospace"
+                     (Mac) "SF Mono,Menlo,Monaco,Courier New,monospace"
+                   (Linux) "Source Code Pro,DejaVu Sans Mono,Courier New,monospace"
+                  (others) "DejaVu Sans Mono,Courier New,monospace"]],
       },
       desc = [=[
         This is a list of fonts which will be used for the GUI version of Vim.