FDO exception thrown up if clicking but no draging with SelectRadius

[liuar]

1. open basic weblayout in chrome or safari
   
2. right click in map -> select more -> radius
   
3. click blank area in map
   

Result: alert exception appears to say 'an exception occured in FDO component'. 'FdoFgfLinearRing::Reset': Cannot execute function due to invalid value for the input parameter(s) 'positions'.

IE got the same exception but not displayed.

[liuar]

There will be a CURVEPOLYGON created when draging or clicking if the user chooses SelectRadius.

For draging, a valid CURVEPOLYGON will be create by the center and radius.
But for clicking, the radius will be 0 and the created CURVEPOLYGON will like:

CURVEPOLYGON ((7.629521563329069 19.93939991157145 (CIRCULARARCSEGMENT (9.193306642292184 18.375614832608335, 10.757091721255298 19.93939991157145), CIRCULARARCSEGMENT (9.193306642292184 21.503184990534564, 7.629521563329069 19.93939991157145))))

which is not a valid CURVEPOLYGON. That's why there's an exception thrown up. IE has the same problem but the exception is not displayed to user.

To resolve this problem, we can try to validate the value of the radius before creating the CURVEPOLYGON. If the value equals to 0, just return.

[liuar]

Fixed in changeset [4772]