[pacman-dev] [PATCH] Clean up MD5 code.

Dan McGee dpmcgee at gmail.com
Thu Aug 16 14:45:40 EDT 2007


On 8/16/07, Xavier <shiningxc at gmail.com> wrote:
> On Thu, Aug 16, 2007 at 01:36:31PM -0400, Dan McGee wrote:
> > 2. Watch your mallocs, and use calloc when possible. You didn't
> > allocate space for the null byte, so you were overrunning your buffers
> > when you filled them and the free() failed when using mtrace(). I
> > switched to calloc usage, and now use sprintf because this is a case
> > where we can do that- it is faster and we aren't worried about running
> > out of room. We then need to take care of the null byte ourselves,
> > however.
> >
>
> Why is it better to use calloc?
> And when using calloc, is it still needed to set the null byte a second time?

Calloc initializes any memory to zero, which can help solve debugging
issues a lot easier when something goes wrong. In addition, it is very
clear how much and of what size memory you need with it.

Regarding the null byte thing- calloc zeros the memory, and while I
would assume that is the same as the null byte, I don't want to take
it for granted, so I figured I'd set it explicitly anyway.

-Dan




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