Do not log unless all connect() attempts fail

IPv6 hosts are often unreachable on the primarily IPv4 Internet and
therefore we shouldn't print an error if there are still other hosts we
can try to connect() to. This helps "git fetch --quiet" stay quiet.

Signed-off-by: Dave Zarzycki <zarzycki@apple.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

connect.c

@@ -192,7 +192,8 @@ static const char *ai_name(const struct addrinfo *ai)
  */
 static int git_tcp_connect_sock(char *host, int flags)
 {
-	int sockfd = -1, saved_errno = 0;
+	struct strbuf error_message = STRBUF_INIT;
+	int sockfd = -1;
 	const char *port = STR(DEFAULT_GIT_PORT);
 	struct addrinfo hints, *ai0, *ai;
 	int gai;
@@ -219,18 +220,12 @@ static int git_tcp_connect_sock(char *host, int flags)
 	for (ai0 = ai; ai; ai = ai->ai_next) {
 		sockfd = socket(ai->ai_family,
 				ai->ai_socktype, ai->ai_protocol);
-		if (sockfd < 0) {
-			saved_errno = errno;
-			continue;
-		}
-		if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
-			saved_errno = errno;
-			fprintf(stderr, "%s[%d: %s]: errno=%s\n",
-				host,
-				cnt,
-				ai_name(ai),
-				strerror(saved_errno));
-			close(sockfd);
+		if ((sockfd < 0) ||
+		    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
+			strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
+				    host, cnt, ai_name(ai), strerror(errno));
+			if (0 <= sockfd)
+				close(sockfd);
 			sockfd = -1;
 			continue;
 		}
@@ -242,11 +237,13 @@ static int git_tcp_connect_sock(char *host, int flags)
 	freeaddrinfo(ai0);
 
 	if (sockfd < 0)
-		die("unable to connect a socket (%s)", strerror(saved_errno));
+		die("unable to connect to %s:\n%s", host, error_message.buf);
 
 	if (flags & CONNECT_VERBOSE)
 		fprintf(stderr, "done.\n");
 
+	strbuf_release(&error_message);
+
 	return sockfd;
 }