fix(all): stabilize login and proxy-aware game startup

go/internal/client/app/game_proxy.go

@@ -0,0 +1,89 @@
+package app
+
+import (
+	"net"
+	"net/url"
+	"strings"
+)
+
+// Unity reads these variables before managed plugins can run.
+func gameProxyEnvironment(environment []string, systemProxy string) []string {
+	result := append([]string(nil), environment...)
+	lookup := func(name string) (int, string) {
+		for index, entry := range result {
+			key, value, found := strings.Cut(entry, "=")
+			if found && strings.EqualFold(key, name) {
+				return index, value
+			}
+		}
+		return -1, ""
+	}
+	if index, _ := lookup("UNITY_PROXYSERVER"); index < 0 && validUnityProxy(systemProxy) {
+		result = append(result, "UNITY_PROXYSERVER="+systemProxy)
+	}
+	index, bypass := lookup("UNITY_NOPROXY")
+	parts := strings.FieldsFunc(bypass, func(character rune) bool { return character == ',' || character == ';' })
+	for _, local := range []string{"localhost", "127.0.0.1", "::1"} {
+		present := false
+		for _, part := range parts {
+			if strings.EqualFold(strings.TrimSpace(part), local) {
+				present = true
+			}
+		}
+		if !present {
+			parts = append(parts, local)
+		}
+	}
+	entry := "UNITY_NOPROXY=" + strings.Join(parts, ",")
+	if index >= 0 {
+		result[index] = entry
+	} else {
+		result = append(result, entry)
+	}
+	return result
+}
+
+func validUnityProxy(proxy string) bool {
+	parsed, err := url.Parse(proxy)
+	if err != nil || parsed.Scheme != "http" || parsed.User != nil || parsed.RawQuery != "" || parsed.Fragment != "" || parsed.Path != "" {
+		return false
+	}
+	host, port, err := net.SplitHostPort(parsed.Host)
+	if err != nil || host == "" || port == "" {
+		return false
+	}
+	_, err = net.LookupPort("tcp", port)
+	return err == nil
+}
+
+// Unity accepts one proxy, so per-scheme configurations must agree.
+func sharedWindowsProxy(raw string) string {
+	if !strings.Contains(raw, "=") {
+		proxy := "http://" + strings.TrimSpace(raw)
+		if validUnityProxy(proxy) {
+			return proxy
+		}
+		return ""
+	}
+	var httpProxy, httpsProxy string
+	for _, entry := range strings.Split(raw, ";") {
+		key, value, found := strings.Cut(strings.TrimSpace(entry), "=")
+		if !found {
+			return ""
+		}
+		switch strings.ToLower(key) {
+		case "http":
+			httpProxy = value
+		case "https":
+			httpsProxy = value
+		}
+	}
+	if httpProxy == "" || !strings.EqualFold(httpProxy, httpsProxy) {
+		return ""
+	}
+	proxy := "http://" + httpProxy
+	if validUnityProxy(proxy) {
+		return proxy
+	}
+	return ""
+}