[Bug-gsl] Wrong orthogonalization in gsl_rng_gfsr4

[Andreas Schneider]

From rng/gfsr4.c:

--8<----

  /* Perform the "orthogonalization" of the matrix */
  /* Based on the orthogonalization used in r250, as suggested initially
   * by Kirkpatrick and Stoll, and pointed out to me by Brian Gough
   */
  for (i=0; i<32; ++i) {
      int k=7+i*3;
      state->ra[k] &= mask;     /* Turn off bits left of the diagonal */
      state->ra[k] |= msb;      /* Turn on the diagonal bit           */
      mask >>= 1;
      msb >>= 1;
  }

  state->nd = i;

---->8--

As pointed out in rng/r250.c, k should be 7*i+3, not 7+i*3.

Additionally, the initialization of the array index with 32 might be unintended.

Andreas Schneider