From 98db9658136cfc41b496b005c9df537f59aed6b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Mon, 10 Feb 2025 08:54:42 +0100
Subject: [PATCH] url-mode: terminate last virtual line before regex matching

If the last line doesn't have a hard linebreak, it was never NULL
terminated, causing regexec() to crash on an out-of-bounds access.
---
 url-mode.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/url-mode.c b/url-mode.c
index 6fd7f03a..00d38d75 100644
--- a/url-mode.c
+++ b/url-mode.c
@@ -388,10 +388,14 @@ regex_detected(const struct terminal *term, enum url_action action,
         }
     }
 
+    /* Terminate the last line, if necessary */
+    if (vline->len > 0 && vline->utf8[vline->len - 1] != '\0')
+        vline->utf8[vline->len++] = '\0';
+
     for (size_t i = 0; i < ALEN(vlines); i++) {
         const struct vline *v = &vlines[i];
         if (v->utf8 == NULL)
-            continue;;
+            continue;
 
         const char *search_string = v->utf8;
         while (true) {