Re: Oh man is this a bad one...

From: Jeremy Elson (
Date: 05/08/96

> extract_char(ch)... in there it calls free_char(ch), which SHOULD free all
> memory used by a char, right? Then it frees the ch itself with free(ch) then
> ch = NULL; right?


> SO when it returns from free_char, ch SHOUDL = NULL, right?


> SO when it returns from extract_char, ch should be null, right?


All it does is call free(ch); it does not set ch equal to NULL.  ch becomes
a "dangling pointer"; i.e. a pointer that points to unallocated memory.
This is correct behavior as long as that pointer is never used again.

>   while (ch->affected)
>     affect_remove(ch, ch->affected);
>   free(ch);
>   ch = NULL;
> }
> Those last 2 lines should kill the char outta memory, even if it leaves the
> strings and such, right? Well.. I dunno... any help appreiciated.

That code is a mistake!

You must have added that "ch = NULL" to free_char() yourself because the
last statement in the stock db.c's free_char() is simply "free(ch)".

ch is a parameter passed to free_char().  Since C is call-by-value, and not
call-by-reference, setting ch = NULL within free_char() does *NOT* mean
that the value of ch is changed in free_char()'s caller.


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