urlapi: parse IPv6 literals without ENABLE_IPV6

This makes the URL parser API stable and working the same way
independently of libcurl supporting IPv6 transfers or not.

Closes #10660

1 files changed, 9 insertions, 4 deletions

diff --git a/lib/inet_ntop.c b/lib/inet_ntop.c
index 024f8da36..770ed3a59 100644
--- a/lib/inet_ntop.c
+++ b/lib/inet_ntop.c
@@ -42,6 +42,15 @@
 #define INT16SZ          2
 
 /*
+ * If ENABLE_IPV6 is disabled, we still want to parse IPv6 addresses, so make
+ * sure we have _some_ value for AF_INET6 without polluting our fake value
+ * everywhere.
+ */
+#if !defined(ENABLE_IPV6) && !defined(AF_INET6)
+#define AF_INET6 (AF_INET + 1)
+#endif
+
+/*
  * Format an IPv4 address, more or less like inet_ntop().
  *
  * Returns `dst' (as a const)
@@ -72,7 +81,6 @@ static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size)
   return dst;
 }
 
-#ifdef ENABLE_IPV6
 /*
  * Convert IPv6 binary address into presentation (printable) format.
  */
@@ -168,7 +176,6 @@ static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size)
   strcpy(dst, tmp);
   return dst;
 }
-#endif  /* ENABLE_IPV6 */
 
 /*
  * Convert a network format address to presentation format.
@@ -187,10 +194,8 @@ char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size)
   switch(af) {
   case AF_INET:
     return inet_ntop4((const unsigned char *)src, buf, size);
-#ifdef ENABLE_IPV6
   case AF_INET6:
     return inet_ntop6((const unsigned char *)src, buf, size);
-#endif
   default:
     errno = EAFNOSUPPORT;
     return NULL;