[Richard Turner <turner@xxxxxxxxx>]

In Wireshark/ui/qt/main_window.h there is a private member variable 
defined as:

capture_file *cap_file_;

I think it's a pointer to the global variable "cfile" (defined in tshark.c).

Is it true that we keep this pointer only to verify the validity of 
cfile (we set cap_file_ to NULL when the capture file is closed)?

Regards,
-Richard Turner