diff -r e254398fcc7c -r 20ca0a6be175 sources/network/ipaddress.cpp
--- a/sources/network/ipaddress.cpp	Wed Jan 27 13:17:11 2021 +0200
+++ b/sources/network/ipaddress.cpp	Wed Jan 27 14:04:53 2021 +0200
@@ -71,9 +71,9 @@
 	String val;
 
 	if (withport == WITH_PORT)
-		val.sprintf ("%u.%u.%u.%u:%u", octet (0), octet (1), octet (2), octet (3), port);
+		val = sprintf ("%u.%u.%u.%u:%u", octet (0), octet (1), octet (2), octet (3), port);
 	else
-		val.sprintf ("%u.%u.%u.%u", octet (0), octet (1), octet (2), octet (3));
+		val = sprintf ("%u.%u.%u.%u", octet (0), octet (1), octet (2), octet (3));
 
 	return val;
 }
@@ -145,11 +145,11 @@
 {
 	unsigned int parts[4];
 	int colonpos = input.find (":");
-	String addressString = colonpos == -1 ? input : input.mid (0, colonpos);
+	String addressString = colonpos == -1 ? input : mid(input, 0, colonpos);
 	IPAddress value;
 
 	// Try scanf the IPv4 host first
-	if (sscanf (addressString, "%u.%u.%u.%u", &parts[0], &parts[1], &parts[2], &parts[3]))
+	if (sscanf(addressString.data(), "%u.%u.%u.%u", &parts[0], &parts[1], &parts[2], &parts[3]))
 	{
 		for (int i : range(4))
 			value.set_octet (i, parts[i]);
@@ -161,7 +161,13 @@
 	}
 
 	if (colonpos != -1)
-		value.port = (unsigned short) input.mid (colonpos + 1, -1).toInt();
+	{
+		std::optional<long> opt = to_int(mid(input, colonpos + 1, -1).data());
+		if (opt.has_value())
+		{
+			value.port = opt.value();
+		}
+	}
 
 	return value;
 }
@@ -175,7 +181,7 @@
 	memset (&hints, 0, sizeof hints);
 	hints.ai_family = AF_INET;
 
-	if (getaddrinfo (node, nullptr, &hints, &lookup) != 0)
+	if (getaddrinfo(node.data(), nullptr, &hints, &lookup) != 0)
 		throw StringParseError ("unknown host " + node);
 
 	IPAddress result;