There're cases when we might want to invoke processes by paths which contain predefined system variables ("%windir%", "%programfiles%" etc.). In such cases protecting the path with the single pair of double quotes might not be enough. E.g. currently 'cmd /c "%programfiles%\prog.exe"' gives us '"C:\Program" is not recognized ...'.
Let's detect the arguments which might contain expanding variables and use an additional pair of quotes for them.
Signed-off-by: Andrey Drobyshev andrey.drobyshev@virtuozzo.com