Re: [9fans] manual suggestions and upas/fs bug

["Douglas A. Gwyn" <DAGwyn@null.net>]

Lucio De Re wrote:
>         char *p0 = realloc(p, n);
>         if (p0 == 0)
>                 panic ("realloc failed");
>         p = p0;
> would be a lot saner.  I forget the semantics, but realloc(p, n) need
> not return p even if the reallocation succeeds.  What I don't know is
> what happens to the space pointed to by p, I assume it's released.

Actually you don't have to be very careful if you're going to abort
anyway.  (Although the returned pointer needs to be checked, even
for a shrink request.)  But if you want to recover more intelligently,
you don't want to lose the old pointer if the realloc fails; either
the old data needs to be retained (so you need to use the old pointer)
or else you want to free the old storage (otherwise you have a memory
leak, which will exacerbate the tight-storage situation).