X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/52112bad8df0cb279c147dbeb42526aeeed07011..31393e34a75043e8b46834d284a08fc45402c707:/settings.c

diff --git a/settings.c b/settings.c
index 934f186f..af5a1b20 100644
--- a/settings.c
+++ b/settings.c
@@ -382,11 +382,11 @@ static void wprefs(void *sesskey, char *name,
 	const char *s = val2key(mapping, nvals,
                                 conf_get_int_int(conf, primary, i));
 	if (s) {
-            maxlen += 1 + strlen(s);
+            maxlen += (maxlen > 0 ? 1 : 0) + strlen(s);
         }
     }
 
-    buf = snewn(maxlen, char);
+    buf = snewn(maxlen + 1, char);
     p = buf;
 
     for (i = 0; i < nvals; i++) {
@@ -397,7 +397,8 @@ static void wprefs(void *sesskey, char *name,
 	}
     }
 
-    assert(p - buf == maxlen - 1);     /* maxlen counted the NUL */
+    assert(p - buf == maxlen);
+    *p = '\0';
 
     write_setting_s(sesskey, name, buf);