bug in cor.m, 3.4.0

[Michael Creel]

I sent a report to the tracker as follows:

On ver 3.4.0, cor fails with 1 argument. corrfcoef works properly. I
believe this also affects the devel sources based on inspection, but I
have not checked with a compiled version.
Code that shows the problem:
octave:1> a = rand(10,2);
octave:2> cor(a)
error: cov: X and Y must have the same number of observations
A possible fix: in cor.m, change
function retval = cor (x, y = [])
to
function retval = cor (x, y = x)

Best,
Michael