Comment 5 for bug 1478168

attached is a proposed partial fix for this bug. In the original code, if you multiplied a non-zero sbasis of size 1 by a zero sbasis of size 1, you would get a zero sbasis of size 2. This will lead to problems downstream since it is the difference between a straight line and a cubic Bezier. This particular product was happening very frequently in the Bend Path LPE. In the new code the product will always be set to be of size 1, since it is zero.
   This does not entirely fix the crash but it seems to make it more difficult to reproduce. Originally I could get a crash just by clicking on the Add button, without even doing a paste. Now a paste is required before it crashes.