X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/be3ed0da8343bdbd68665bef9a9bb096865bea04..d9e0300f903aa7cfb85a94480ad544082a7a6c35:/logging.c

diff --git a/logging.c b/logging.c
index db02892a..17924c5a 100644
--- a/logging.c
+++ b/logging.c
@@ -384,7 +384,7 @@ static void xlatlognam(Filename *dest, Filename src,
 	    char c;
 	    s++;
 	    size = 0;
-	    if (*s) switch (c = *s++, tolower(c)) {
+	    if (*s) switch (c = *s++, tolower((unsigned char)c)) {
 	      case 'y':
 		size = strftime(buf, sizeof(buf), "%Y", tm);
 		break;