From 2845e5322f191aa735cd1e32c4774a82d3af4bf0 Mon Sep 17 00:00:00 2001
From: ahgamut <41098605+ahgamut@users.noreply.github.com>
Date: Sun, 4 Jul 2021 19:39:57 +0530
Subject: [PATCH] gethostbyname inet_pton fix

when gethostbyname is provided an IP address in the form of a string, it
is supposed to write the address to h_name; the function instead was
writing an empty string. getaddrinfo does the correct thing by calling
inet_pton and returning on success, and the mistake is in gethostbyname.

The fix is to strlen(result->ai_canonname): If the inet_pton call in
getaddrinfo is successful, ai_canonname will point to valid memory
(non-NULL) but the string will be empty. in this case, the name (which
is an IP address string) will now correctly be copied to h_name of the
hostent structure.
---
 libc/dns/gethostbyname.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libc/dns/gethostbyname.c b/libc/dns/gethostbyname.c
index 27e39a438..0153771ed 100644
--- a/libc/dns/gethostbyname.c
+++ b/libc/dns/gethostbyname.c
@@ -55,7 +55,7 @@ struct hostent *gethostbyname(const char *name) {
   if (getaddrinfo(name, NULL, NULL, &result) || result == NULL) return NULL;
 
   if (ptr0->h_name) free(ptr0->h_name);
-  if (result->ai_canonname) {
+  if (result->ai_canonname && strlen(result->ai_canonname) > 0) {
     ptr0->h_name = strdup(result->ai_canonname);
   } else {
     ptr0->h_name = strdup(name);