From c00231078790e7f700b820a96f69387c42518a10 Mon Sep 17 00:00:00 2001
From: "Justin M. Keyes" <justinkz@gmail.com>
Date: Sun, 3 Jul 2016 01:17:26 -0400
Subject: [PATCH] tui: Assume 256 colors in most cases.

Assume 256 colors if:
  - $TERM contains "xterm" or "256"
  - $COLORTERM contains "256"

Closes #2912
---
 src/nvim/tui/tui.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index ea10130056..d220df508a 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -788,6 +788,7 @@ static void fix_terminfo(TUIData *data)
   unibi_term *ut = data->ut;
 
   const char *term = os_getenv("TERM");
+  const char *colorterm = os_getenv("COLORTERM");
   if (!term) {
     goto end;
   }
@@ -833,10 +834,10 @@ static void fix_terminfo(TUIData *data)
 #define XTERM_SETAB \
   "\x1b[%?%p1%{8}%<%t4%p1%d%e%p1%{16}%<%t10%p1%{8}%-%d%e48;5;%p1%d%;m"
 
-  if (os_getenv("COLORTERM") != NULL
-      && (!strcmp(term, "xterm") || !strcmp(term, "screen"))) {
-    // probably every modern terminal that sets TERM=xterm supports 256
-    // colors(eg: gnome-terminal). Also do it when TERM=screen.
+  if ((colorterm && strstr(colorterm, "256"))
+      || strstr(term, "256")
+      || strstr(term, "xterm")) {
+    // Assume TERM~=xterm or COLORTERM~=256 supports 256 colors.
     unibi_set_num(ut, unibi_max_colors, 256);
     unibi_set_str(ut, unibi_set_a_foreground, XTERM_SETAF);
     unibi_set_str(ut, unibi_set_a_background, XTERM_SETAB);