From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 1 Jan 2026 11:45:45 +0000 (+0100)
Subject: inet_ntop: avoid the strlen()
X-Git-Tag: curl-8_18_0~49
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7d8725a558a154de032368bd42205bab10d1c4f;p=thirdparty%2Fcurl.git

inet_ntop: avoid the strlen()

Also, skip adding the terminating null that is not used.

Closes #20139
---

diff --git a/lib/curlx/inet_ntop.c b/lib/curlx/inet_ntop.c
index 6b4472bab2..6bea5e1db6 100644
--- a/lib/curlx/inet_ntop.c
+++ b/lib/curlx/inet_ntop.c
@@ -181,10 +181,9 @@ static char *inet_ntop6(const unsigned char *src, char *dst, size_t size)
    */
   if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
     *tp++ = ':';
-  *tp++ = '\0';
 
   /* Check for overflow, copy, and we are done. */
-  if((size_t)(tp - tmp) > size) {
+  if((size_t)(tp - tmp) >= size) {
 #ifdef USE_WINSOCK
     errno = WSAEINVAL;
 #else
@@ -193,7 +192,7 @@ static char *inet_ntop6(const unsigned char *src, char *dst, size_t size)
     return NULL;
   }
 
-  curlx_strcopy(dst, size, tmp, strlen(tmp));
+  curlx_strcopy(dst, size, tmp, tp - tmp);
   return dst;
 }