Patch 731209: Restore socketmodule's behaviour with dotted quad addresses
to that of Python2.1. Such nnn.nnn.nnn.nnn addresses are just used directly,
not passed to the resolver for a pointless lookup.
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index b9e9bd4..843c5a9 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -626,6 +626,8 @@
 {
 	struct addrinfo hints, *res;
 	int error;
+	int d1, d2, d3, d4;
+	char ch;
 
 	memset((void *) addr_ret, '\0', sizeof(*addr_ret));
 	if (name[0] == '\0') {
@@ -682,6 +684,20 @@
 		sin->sin_addr.s_addr = INADDR_BROADCAST;
 		return sizeof(sin->sin_addr);
 	}
+	if (sscanf(name, "%d.%d.%d.%d%c", &d1, &d2, &d3, &d4, &ch) == 4 &&
+	    0 <= d1 && d1 <= 255 && 0 <= d2 && d2 <= 255 &&
+	    0 <= d3 && d3 <= 255 && 0 <= d4 && d4 <= 255) {
+		struct sockaddr_in *sin;
+		sin = (struct sockaddr_in *)addr_ret;
+		sin->sin_addr.s_addr = htonl(
+			((long) d1 << 24) | ((long) d2 << 16) |
+			((long) d3 << 8) | ((long) d4 << 0));
+		sin->sin_family = AF_INET;
+#ifdef HAVE_SOCKADDR_SA_LEN
+		sin->sin_len = sizeof(*sin);
+#endif
+		return 4;
+	}
 	memset(&hints, 0, sizeof(hints));
 	hints.ai_family = af;
 	error = getaddrinfo(name, NULL, &hints, &res);