#4965 recttopolar and polartorect are silent no-ops on lists

[David Scherfgen]

recttopolar([1.0],[1.0]) returns [[1.0],[1.0]], the input unchanged

Maxima 5.49post, SBCL 2.6.7.

(%i1) display2d:false$
(%i2) load(fft)$
(%i3) recttopolar([1.0],[1.0]);
(%o3) [[1.0],[1.0]]
(%i4) polartorect([1.0],[float(%pi)/2]);
(%o4) [[1.0],[1.5707963267948966]]

Expected: (%o3) = [[1.4142135623730951],[0.7853981633974483]] — magnitude sqrt(2) and angle %pi/4. (%o4) = [[0.0],[1.0]].

No error or warning is issued; the caller cannot tell the conversion did not happen. fft and inverse_fft in the same package round-trip correctly.