Proposal to speed up some compare functions

[Olaf Frączyk <olaf cbk poznan pl>]

Hi,
I found that in e.g. numeric_compare we use:
  t1 = LIBBALSA_MESSAGE_GET_NO(m1);

this is a macro, but the macro resolves ... to function. So we waste time 
to make another function call.

I changed the function to:

static gint
numeric_compare(GtkCList * clist, gconstpointer ptr1, gconstpointer ptr2)
{
if(!((GtkCListRow*)ptr1)->data || !((GtkCListRow*)ptr2)->data)
return 0;
return(((LibBalsaMessage*)((GtkCListRow*)ptr2)->data)->header->msgno
-((LibBalsaMessage*)((GtkCListRow*)ptr1)->data)->header->msgno);
}

And to make it working you have to add include:
#include "mailbackend.h"

I have compared times for the same mailbox as in my previous mail.

Sorting with original function takes 19-19.5 seconds.
Sorting with the new one takes about 14.5 seconds.

In other places I found similiar constructions.

Regards,

Olaf