hostip: make Curl_printable_address not return anything

It was not used much anyway and instead we let it store a blank buffer
in case of failure.

Reported-by: MonocleAI
Fixes #5411
Closes #5418

1 files changed, 20 insertions, 23 deletions

diff --git a/lib/hostip.c b/lib/hostip.c
index af907262b..025d9a784 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -131,39 +131,36 @@ int Curl_num_addresses(const struct Curl_addrinfo *addr)
 }
 
 /*
- * Curl_printable_address() returns a printable version of the 1st address
+ * Curl_printable_address() stores a printable version of the 1st address
  * given in the 'ai' argument. The result will be stored in the buf that is
  * bufsize bytes big.
  *
- * If the conversion fails, it returns NULL.
+ * If the conversion fails, the target buffer is empty.
  */
-const char *Curl_printable_address(const struct Curl_addrinfo *ai, char *buf,
-                                   size_t bufsize)
+void Curl_printable_address(const struct Curl_addrinfo *ai, char *buf,
+                            size_t bufsize)
 {
-  const struct sockaddr_in *sa4;
-  const struct in_addr *ipaddr4;
-#ifdef ENABLE_IPV6
-  const struct sockaddr_in6 *sa6;
-  const struct in6_addr *ipaddr6;
-#endif
+  DEBUGASSERT(bufsize);
+  buf[0] = 0;
 
   switch(ai->ai_family) {
-    case AF_INET:
-      sa4 = (const void *)ai->ai_addr;
-      ipaddr4 = &sa4->sin_addr;
-      return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr4, buf,
-                            bufsize);
+  case AF_INET: {
+    const struct sockaddr_in *sa4 = (const void *)ai->ai_addr;
+    const struct in_addr *ipaddr4 = &sa4->sin_addr;
+    (void)Curl_inet_ntop(ai->ai_family, (const void *)ipaddr4, buf, bufsize);
+    break;
+  }
 #ifdef ENABLE_IPV6
-    case AF_INET6:
-      sa6 = (const void *)ai->ai_addr;
-      ipaddr6 = &sa6->sin6_addr;
-      return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr6, buf,
-                            bufsize);
+  case AF_INET6: {
+    const struct sockaddr_in6 *sa6 = (const void *)ai->ai_addr;
+    const struct in6_addr *ipaddr6 = &sa6->sin6_addr;
+    (void)Curl_inet_ntop(ai->ai_family, (const void *)ipaddr6, buf, bufsize);
+    break;
+  }
 #endif
-    default:
-      break;
+  default:
+    break;
   }
-  return NULL;
 }
 
 /*