Respect the original SIGWINCH's handler SA_SIGINFO field
Imported from https://developer.pidgin.im/ticket/16680 , authored by
marcus. When chaining the original SIGWINCH, make sure to optionally
call it with the extra arguments that are available when it was
installed with SA_SIGINFO.
#include"gntutils.h"
intmain()
{
GntWidget*win,*button;
gnt_init();
gnt_util_parse_widgets("<vwindow id='0' fill='0' align='2'><label>This is a test.</label><button id='1'>OK</button></vwindow>",2,&win,&button);