From 18db5ae3ae833af302ea0fbfd1e5c633ac73a743 Mon Sep 17 00:00:00 2001
From: Mark Nudelman <markn@greenwoodsoftware.com>
Date: Thu, 22 Jan 2026 08:44:33 -0800
Subject: [PATCH] Fix handling of empty terminfo capabilities.

If a terminfo capability is set to an empty string,
treat it as if it were undefined.

Related to #710.
---
 NEWS      | 2 ++
 screen.c  | 2 ++
 version.c | 3 ++-
 3 files changed, 6 insertions(+), 1 deletion(-)

#diff --git a/NEWS b/NEWS
#index 2ac95d19..02209de1 100644
#--- a/NEWS
#+++ b/NEWS
#@@ -17,6 +17,8 @@
# 
# * Fix bug using negative value with -z option (github #709).
# 
#+* Fix bug handling empty terminfo capabilties (github #710).
#+
# * Fix memory leak in setupterm (github #707).
# 
# ======================================================================
diff --git a/screen.c b/screen.c
index dd8ab292..b8219bf5 100644
--- a/screen.c
+++ b/screen.c
@@ -1298,6 +1298,8 @@ public constant char * special_key_str(int key)
 	default:
 		return (NULL);
 	}
+	if (s != NULL && *s == '\0')
+		s = NULL;
 	return (s);
 }
 
#diff --git a/version.c b/version.c
#index 6cda04a7..0380c3a9 100644
#--- a/version.c
#+++ b/version.c
#@@ -1075,7 +1075,8 @@ v689  12/27/25  Add prompt seqs %C, %W, %Q, ?Q; don't allow any command to
# v690  12/31/25  Cleanup.
# v691  1/10/26   Fix mingw build.
# v692            Fix memory leak in setupterm; clear termio ICRNL|INLCR;
#-                fix bug with negative value in -z.
#+                fix bug with negative value in -z; fix bug with empty 
#+                terminfo caps.
# */
# 
# char version[] = "692x";