crashing as chars log off..

its seems that when i put in the hometowns code by noplex when players go to logg off it kills the mud.. i think its trying to free somethign that doesnt exsist as the exit but i dont know where to look for that typ of thing.. i know ive changed it before for other snippets and such but i just cant seem to remember where.. if anyone know it'd be helpful
thanks -typ

Try using gdb (the debugger) to see why it is crashing. Search for gdb on this forum for some examples of using it.

ok ive used the gdb debugger and it seems thats im getting a BUG: Freeing null pointer db.c:2913
STRFREEing NULL in db.c, line 2913
/* Free Hometown Stuff -Nopey */
STRFREE( ch->pcdata->htown_name );
if( ch->pcdata->hometown )
{
STRFREE( ch->pcdata->hometown->name );
STRFREE( ch->pcdata->hometown->filename ); //this line
DISPOSE( ch->pcdata->hometown );
}

in pc_data there are the lines..
char * htown_name;
HOMETOWN_DATA *hometown;

and the hometown_data structure is
struct hometown_data
{
HOMETOWN_DATA *next;
HOMETOWN_DATA *prev;
char *name;
char *filename;
int recall;
};

im assuming something is all screwy in there but how would i go about checking what exactly is goin on there thats making it die.

ok a little update...
this char that i made (jon) is a newcreated char.. with the hometown selected when he created.. for any other char its fine they can log on and off but with jon when i go to log off i get that strfree null stuff.
where i was getting that error in db.c i put in bugs to display the name of the filename and what not that was causing the crash. well heres the code i put in and what i got in return
if( ch->pcdata->hometown )
{
bug("%s",ch->pcdata->hometown->name);
STRFREE( ch->pcdata->hometown->name );
bug("%s",ch->pcdata->hometown->filename);
STRFREE( ch->pcdata->hometown->filename );
DISPOSE( ch->pcdata->hometown );
}
Sat Jun 29 09:44:15 2002 :: Jon has quit (Room 10385).
Sat Jun 29 09:44:15 2002 :: [*****] BUG:
Sat Jun 29 09:44:15 2002 :: [*****] BUG: (null)
Sat Jun 29 09:44:15 2002 :: [*****] BUG: Freeing null pointer db.c:2915
STRFREEing NULL in db.c, line 2915

It seems pretty clear from both the original crash and your debugging that the field ch->pcdata->hometown->filename is NULL (ie. zero).

When you create a hometown you should put something into that field, alternatively check it is not null before you free it, like this:

well all in all it seemed easier to rewrite the whole hometown thing so thats what im nthe process of doing :-p i did like the hometown code by noplex but there were a bunch of glitchs i had to go find.. it seems as if it would work on a stock smaug mud fhowever im not running a stock one at this point :-p thanks for you help