Re: [CODE] CREATE() buglet

From: George (greerga@CIRCLEMUD.ORG)
Date: 07/07/98

On Tue, 7 Jul 1998, Dean Takemori wrote:

>Angus Mezick <angus@EDGIL.CCMAIL.COMPUSERVE.COM> wrote:
>>why are you trying to call CREATE with 0 or a negative number anyway?  C will
>num = strlen(somestring) + 1;
>p = (char*)malloc(num);
>if (p == NULL) { abort(); }
>Contrived example addmittedly, but this will bomb immediately on
>some systems and silently corrupt memory in others.

The point being, if the program asked for 0 bytes, it should use 0 bytes.
That may sound a bit strange, but it's what you do with malloc() already.
You ask for 50 bytes, you use 50 bytes or less.  Ask for 0 bytes and use 0
bytes or less.  Chances are you'll crash anyway if you overwrite a pointer
to 0 bytes.

>"d. hall" <dhall@OOI.NET> wrote:
>>Quite a few programmers make wrappers for malloc to one: assert(3) that
>>requested length is > 0, and if the return is non-null.  Quite of few
>And this is what CREATE() is, so we should be complete and check for
>num > 0.  Values that when cast to signed are negative are another

Why check for 'num > 0'?  Perhaps you mean MSB set?

eh, might as well

George Greer, | Genius may have its limitations, but          | stupidity is not thus handicapped.    |                  -- Elbert Hubbard

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