C Wrapper Function, crashing Python?

[Java and Swing]

Bernhard Herzog wrote:
> "Java and Swing" <codecraig at gmail.com> writes:
>
> > char *foo(const char *in) {
> >     char *tmp;
> >     tmp = (char *) malloc((strlen(in) * sizeof(char)) + 1);
> >     strcpy(tmp, in);
> >     ...
> >     ...
> >     free(tmp);
> >     return someValue;
> > }
> >
> > Is that appropriate?  I was under the impression that when you malloc
> > memory, you free it when done.
>
> Looks fine.  I hope someValue does not point somewhere into the tmp
> buffer, though.

  someValue doesn't.

>
> > I also have things like...
> >
> > char *bar(char *in) {
> >     char *results, *finalResults;
> >     results = (char *) malloc(...);
> >     finalResults = results;
> >
> >     while (...) { *results++ = some_val; }
> >
> >     return finalResults;
> > }
>
> Seems OK, too, assuming the results buffer is big enough.

    results = (char *) malloc((sizeof(char) * strlen(in) + 1);
    ..should be big enough.  At any rate, it works four times in a row
before it fails.

    I wonder what else or how else to solve this.  Why is malloc'ing
the memory crashing it!?