From: Eli Zaretskii <eliz@gnu.org>
Date: Thu, 11 Nov 2021 14:55:11 +0000 (+0200)
Subject: Fix 8-color PuTTY -nw sessions broken by a recent commit
X-Git-Tag: emacs-29.0.90~3668^2~45
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=386289bdc8461898b05f318b77e0bedf2509537d;p=emacs.git

Fix 8-color PuTTY -nw sessions broken by a recent commit

* src/term.c (init_tty): Fix the change which introduced support
for the terminfo Tc flag.  The code as installed broke colors in
PuTTY -nw sessions, because 'tigetflag' returned -1, which is
non-zero, so it was treated as the sign that true color is
supported.  But if the value returned by 'tigetflag' is -1, it means
the capability is not a boolean one, so that's not to be used as a
valid support for 24-bit color.  (Bug#44950)
---

diff --git a/src/term.c b/src/term.c
index d86ae12ba84..51fcef6f1ec 100644
--- a/src/term.c
+++ b/src/term.c
@@ -4155,7 +4155,7 @@ use the Bourne shell command 'TERM=...; export TERM' (C-shell:\n\
 	/* Fall back to xterm+direct (semicolon version) if Tc is set
 	   (de-facto standard introduced by tmux) or if	requested by
 	   the COLORTERM environment variable.  */
-	else if (tigetflag("Tc")
+	else if ((tigetflag("Tc") != -1)
 		 || ((bg = getenv("COLORTERM")) != NULL
 		     && strcasecmp(bg, "truecolor") == 0))
 	  {