Sys.environment decodes the Windows environment as UTF-8 #117

On Windows Sys.environment() reads the narrow environ, which is in the ANSI code page, and decodes it as UTF-8, while Sys.getEnv uses the wide API. So after putEnv("X", "café 日本"), getEnv("X") and environment()["X"] differ, and any non-ASCII value (such as a user profile path) is garbled.