tolower(3) guarantees to return its argument unchanged if it's not

uppercase.
While here use the correct idiom of casting to unsigned char.

OK millert, farewell to ultrix deraadt

1 files changed, 3 insertions, 10 deletions

diff --git a/src/lib/libc/net/res_comp.c b/src/lib/libc/net/res_comp.c
index e637f4a958..41a1c9771a 100644
--- a/src/lib/libc/net/res_comp.c
+++ b/src/lib/libc/net/res_comp.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: res_comp.c,v 1.20 2016/05/01 15:17:29 millert Exp $   */
+/*      $OpenBSD: res_comp.c,v 1.21 2022/11/16 18:30:12 florian Exp $   */
 
 /*
  * ++Copyright++ 1985, 1993
@@ -261,14 +261,6 @@ __dn_skipname(const u_char *comp_dn, const u_char *eom)
         return (cp - comp_dn);
 }
 
-static int
-mklower(int ch)
-{
-        if (isascii(ch) && isupper(ch))
-                return (tolower(ch));
-        return (ch);
-}
-
 /*
  * Search for expanded name from a list of previously compressed names.
  * Return the offset from msg if found or -1.
@@ -296,7 +288,8 @@ dn_find(u_char *exp_dn, u_char *msg, u_char **dnptrs, u_char **lastdnptr)
                                                 goto next;
                                         if (*dn == '\\')
                                                 dn++;
-                                        if (mklower(*dn++) != mklower(*cp++))
+                                        if (tolower((unsigned char)*dn++) !=
+                                            tolower((unsigned char)*cp++))
                                                 goto next;
                                 }
                                 if ((n = *dn++) == '\0' && *cp == '\0')