strncmp: bug comparing two character arrays

[Thorsten Meyer]

Hi,

while patching the bug just reported I found another one in octave mercurial:

octave:56> strncmp(["ab";"cd"], ["ab";"ce"], 2)
ans =  1
octave:57> strncmp(["ab";"cd"], ["ab";"ce"], 3)
ans =  1
octave:58> strncmp(["ab";"cd"], ["ab";"ce"], 4)
ans = 0

The relevant part of the source code in src/strfns.cc is here:

	      for (int i = 0; i < n; i++)
		{
		  if (s1(i) != s2(i))
		    {
		      retval = false;
		      return retval;
		    }
		}

	      retval = true;

So strncmp compares the first n elements of the complete character array and not the first n
elements of each  string in the character array.

I can probably provide a patch for the 2d-case. But what should the function do in case of two n
dimensional character arrays with n>2 (and how do I index into an n-d array?)?

regards

Thorsten