From d8963c434f01e6a7316fa5a1dad35f95c7ca73b7 Mon Sep 17 00:00:00 2001
From: Thomas Fehér <thomas.feher@yahoo.de>
Date: Sat, 12 Sep 2020 07:43:35 +0200
Subject: Fix colors in terminal by maintaining COLORTERM

Fixes https://github.com/neovim/neovim/issues/10836
---
 src/nvim/os/pty_process_unix.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

(limited to 'src/nvim/os/pty_process_unix.c')

diff --git a/src/nvim/os/pty_process_unix.c b/src/nvim/os/pty_process_unix.c
index f0bc13783c..4d7d9a45df 100644
--- a/src/nvim/os/pty_process_unix.c
+++ b/src/nvim/os/pty_process_unix.c
@@ -160,8 +160,21 @@ static void init_child(PtyProcess *ptyproc)
   os_unsetenv("COLUMNS");
   os_unsetenv("LINES");
   os_unsetenv("TERMCAP");
-  os_unsetenv("COLORTERM");
   os_unsetenv("COLORFGBG");
+  // setting COLORTERM to "truecolor" if termguicolors is set and 256
+  // otherwise, but only if it was set in the parent terminal at all
+  if (os_env_exists("COLORTERM")) {
+    const char *colorterm = os_getenv("COLORTERM");
+    if (colorterm != NULL) {
+      if (p_tgc) {
+        os_setenv("COLORTERM", "truecolor", 1);
+      } else {
+        os_setenv("COLORTERM", "256", 1);
+      }
+    } else {
+      os_unsetenv("COLORTERM");
+    }
+  }
 
   signal(SIGCHLD, SIG_DFL);
   signal(SIGHUP, SIG_DFL);
-- 
cgit