error out if string is too long

cmd/watchdog/installer/install_windows.go

@@ -74,6 +74,9 @@ func install(c *Config) error {
 	// "C:\Users\aj\.local\opt\appname\appname.js /c -p 8080"
 	// "C:\Program Files (x64)\nodejs\node.exe /c C:\Users\aj\.local\opt\appname\appname.js -p 8080"
 	regSZ := bin + setArgs + strings.Join(c.Argv, " ")
+	if len(regSZ) > 260 {
+		return fmt.Errorf("data value is too long for registry entry")
+	}
 	fmt.Println("Set Registry Key:")
 	fmt.Println(autorunKey, c.Title, regSZ)
 	k.SetStringValue(c.Title, regSZ)