Set SO_KEEPALIVE option on native git:// sockets.

Signed-off-by: Michal Ludvig <michal@logix.cz>

Index: git-1.4.0/connect.c
===================================================================
--- git-1.4.0.orig/connect.c
+++ git-1.4.0/connect.c
@@ -331,7 +331,7 @@ static int git_tcp_connect_sock(char *ho
 	char *colon, *end;
 	char *port = STR(DEFAULT_GIT_PORT);
 	struct addrinfo hints, *ai0, *ai;
-	int gai;
+	int gai, option;
 
 	if (host[0] == '[') {
 		end = strchr(host + 1, ']');
@@ -363,6 +363,10 @@ static int git_tcp_connect_sock(char *ho
 				ai->ai_socktype, ai->ai_protocol);
 		if (sockfd < 0)
 			continue;
+
+		option = 1;
+		setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
+
 		if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 			close(sockfd);
 			sockfd = -1;
@@ -392,7 +396,7 @@ static int git_tcp_connect_sock(char *ho
 	struct hostent *he;
 	struct sockaddr_in sa;
 	char **ap;
-	unsigned int nport;
+	unsigned int nport, option;
 
 	if (host[0] == '[') {
 		end = strchr(host + 1, ']');
@@ -433,6 +437,9 @@ static int git_tcp_connect_sock(char *ho
 		sa.sin_port = htons(nport);
 		memcpy(&sa.sin_addr, *ap, he->h_length);
 
+		option = 1;
+		setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
+
 		if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 			close(sockfd);
 			sockfd = -1;