ST_OffsetCurve returns EMPTY line from non-empty input

[strk]

If the line is short relatively to the offset, OffsetCurve can return EMPTY:

=# select ST_AsText(ST_OffsetCurve('LINESTRING(24 0,24.00001 0)'::geometry, 3));
LINESTRING(24 3,24.00001 3)
=# select ST_AsText(ST_OffsetCurve('LINESTRING(24 0,24.000001 0)'::geometry, 3));
LINESTRING EMPTY

Spotted here: ​https://github.com/azavea/nyc-trees/issues/1728

[mdavis]

This is now fixed.