From c84ba83cf1a50d1f892d745c62d9dabb513f3e91 Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Sun, 21 Sep 2025 12:12:37 +0800
Subject: [PATCH] fix(options): increase t_Co buffer size (#35859)

(cherry picked from commit c2136e3590082c20fbc210a5578530b2625bf47e)
---
 src/nvim/option.c                   | 6 ++----
 test/functional/ui/options_spec.lua | 7 ++++++-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/nvim/option.c b/src/nvim/option.c
index d5a4d5b08f..d1993756a8 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2989,8 +2989,6 @@ bool is_tty_option(const char *name)
   return find_tty_option_end(name) != NULL;
 }
 
-#define TCO_BUFFER_SIZE 8
-
 /// Get value of TTY option.
 ///
 /// @param  name  Name of TTY option.
@@ -3004,8 +3002,8 @@ OptVal get_tty_option(const char *name)
     if (t_colors <= 1) {
       value = xstrdup("");
     } else {
-      value = xmalloc(TCO_BUFFER_SIZE);
-      snprintf(value, TCO_BUFFER_SIZE, "%d", t_colors);
+      value = xmalloc(NUMBUFLEN);
+      snprintf(value, NUMBUFLEN, "%d", t_colors);
     }
   } else if (strequal(name, "term")) {
     value = p_term ? xstrdup(p_term) : xstrdup("nvim");
diff --git a/test/functional/ui/options_spec.lua b/test/functional/ui/options_spec.lua
index 211fc1dc77..ce52883b0b 100644
--- a/test/functional/ui/options_spec.lua
+++ b/test/functional/ui/options_spec.lua
@@ -228,7 +228,12 @@ describe('UI can set terminal option', function()
   it('term_colors', function()
     eq('256', eval '&t_Co')
 
-    local _ = Screen.new(20, 5, { term_colors = 8 })
+    local screen = Screen.new(20, 5, { term_colors = 8 })
     eq('8', eval '&t_Co')
+    screen:detach()
+
+    screen = Screen.new(20, 5, { term_colors = 16777216 })
+    eq('16777216', eval '&t_Co')
+    screen:detach()
   end)
 end)