Currently, curves have a default offset of 1.0, while the initial (and
expected) value is 0.0. When resetting this value to its default, the
curve is now modified unexpectedly. This is most noticeable with text
objects: when resetting the offset of a new text, it will look very
broken.
Internally the value is stored with an offset of 1.0, with custom
setter and getter adding and subtracting 1.0 respectively. To give
this property a default of 0.0, we need to add 1.0 to the initial
value upon curve creation.
Damien Picard