08528f577d
A description of the problem is found in https://developer.blender.org/T36425#19 . The cause of the issue was identified as roudning errors in Operators::createStroke() due to insufficient numerical precision. Precision promotion from float to double was done in the return values of getPoint3D/2D methods in Interface0D and its subclasses in C++ (data members stored in the 0D classes have already been in double precision).