sorting

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Problem: Program crashes when using NSArray's sortedArrayUsingFunction:context:

      Old code used qsort like this:

id cells = [matrix itemList];
if (cells) {
      qsort(NX_ADDRESS(cells), [cells count], sizeof(id *), cellcmp);
}
      And called this function:

static int cellcmp(const void *first, const void *second)
{
      const char *s1 = [*((id *)first) title];
      const char *s2 = [*((id *)second) title];
      return (s1 && s2) ? strcmp(s1, s2) : 0;
}

      Newly ported code uses NSMatrix's sorting function:

       [matrix sortUsingFunction:celltitlecmp context:NULL];

      And called this function (which crashed the program):

      static int celltitlecmp(id first, id second)
      {
            return [[first title] compare:[second title]];
      }

Solution: New function didn't prototype the compare function correctly, note that it needs a third, void *, parameter:

      static int celltitlecmp(id first, id second,void *userdata)
      {
            return [[first title] compare:[second title]];
      }

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Created by Stone Design's Create on 6/2/1997