I found a bug in AdvApprox_ApproxAFunction::Approximation(...). The last parameter of this function, namely 'ErrorCode', should propagate an error state if the approximation was not successfull.
But line 560 which read in OCC version 5.2
is now commented out
// pour l'instant ErrorCode=-1;
This has the effect that e.g. in Geom2dConvert_ApproxCurve the IsDone() method always returns true, even when the approximation did not succeed, i.e. when MaxError is greater than the specified Tol2d.
After I restored the original ErrorCode statement in AdvApprox_ApproxAFunction the Geom2dConvert_ApproxCurve behaves as it should: if MaxError > Tol2d, then IsDone() == Standard_False. So far I could not detect any side effects.
Kind regards, Kris.