[Octave-bug-tracker] [bug #60620] [octave forge] (optim) 'expfit' function from optim-1.6.1 package terminates with segmentation fault

[anonymous]

Follow-up Comment #12, bug #60620 (project octave):

I have modified 'expfit.m' this way - the bottom line is the offending one:

"
foo.one = A(:,1:deg);
foo.two = A(:,deg+1);
output_precision(25);
save_precision(25);
save('-text', 'foo.txt', 'foo');
s = - A(:,1:deg) \ A(:,deg+1);
".
As expected, the segfault is still present.

After the segfault the offending data is found in 'foo.txt' file.

After the segfault I invoke Octave again and from prompt do:

"
octave:13> load('-text', 'foo.txt', 'foo')
octave:14> s = - foo.one\foo.two
s =

   5.943788696566891793793275e-01
   6.243336229322766772753539e-01
   4.071329687950496767356867e-01
   4.019410952178621987407325e-01
  -2.517268467102328211026929e-01
  -7.948153211805004669798791e-01
  -7.127222427414680039348127e-01
  -1.457716297133185845424919e+00
  -1.518863854985087247229103e+00
  -7.496244257374140573801924e-01
  -1.041980051013670305337655e+00
  -4.580327435624297338634392e-01
   2.453953542006280796883289e-01
   7.360050855365433131183295e-01
   1.825649089808825786818147e+00
   7.020672768678591912916431e-01
".

I.e. even though the data is supposedly the same that caused segfault, when
saved and then loaded it doesn't cause segfault.

I do not know how to explain this. Rounding errors slightly changing data and
thus eliminating segfault ? Some parser error causing the offending 's = -
A(:,1:deg) \ A(:,deg+1);' line to do something else ?

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