0028493: [Regression vs 7.0.0] Intersection algorithm produces curve with loop 1. New testgrid "lowalgos/intss" has been created. It will contain all test cases on geometrical intersection of two surfaces ("intersect" DRAW-command) and two faces ("bopcurves" DRAW-command). 2. New test case for the issue #28493 has been created because the problem is not reproduced on MASTER. 3. Test case (lowalgos/intss/bug24472) for the issue #29501 has been modified in order to check loops of the resulting intersection curves.

0028222: Intersection of two cylinders fails 1. The reason of exception has been eliminated. 2. Algorithm in IntPatch_WLineTool::JoinWLines(...) method has been modified in order to forbid join curves in the point where more than two intersection lines meet. More over, joining is forbidden if local curvature in the connection point is too big (see function CheckArgumentsToJoin(...) in the file IntPatch_WLineTool.cxx). 3. Interface of IntPatch_WLineTool::JoinWLines(...) method has been modified in order to reduce number of arguments. 4. Small corrections in IsSeamOrBound(...) static function has been made. Namely, check has been added if two boundaries are in the same period region but are too far each to other (see IntPatch_WLineTool.cxx, IsSeamOrBound(...) function, line # 532). 5. "Reversed" flag has been made local. Now, it is pure local characteristic: the algorithm decides itself, shall we reverse the argument order. This correction makes the algorithm more commutative (see issue #25404). However, IntPatch_WLineTool::JoinWLines(...) method can return non-commutative result. 6. Algorithm of searching small intersection curves has been improved. 7. New methods have been added in Bnd_Range class. Some test cases have been adjusted according to their new behavior. 1. tests\bugs\modalg_6\bug26310_3 tests\bugs\modalg_6\bug26310_4 tests\bugs\moddata_2\bug235 tests\perf\modalg\bug26310_1 tests\bugs\modalg_5\bug24915 Logic of these cases has been changed. Mover over, additional check has been added in "bug26310_1" test case. Therefore, its performance will be slower than on the current MASTER. 2. tests\bugs\modalg_5\bug25292* Scripts have been rewritten in order to make it more readable. Logic of these cases has not been changed.

0023178: Intersection of cylinders fails to produce results 1. Unification of trimmed and not-trimmed cylinders processing (IntPatch_Intersection::GeomGeomPerfomTrimSurf() method has been removed). 2. Interface of IntPatch_ImpImpIntersection::Perform(...) method has been changed. 3. Now, WLine purging is forbidden for Geom-Geom-Intersection. 4. Bnd_Range class has been created. See Bnd_Range.hxx for detail information. 5. Algorithm of AddBoundaryPoint function has been improved in order to obtain intersection points in both boundaries (VFirst and VLast of every surface). 6. Earlier, method Geom2dConvert::ConcatG1(...) increased resulted B-spline degree (in case of not succession of previous iteration). Now increased value has been limited by Geom2d_BSplineCurve::MaxDegree() value (max degree = 25). 7. Algorithm of B-spline closure definition has been changed in the methods Geom2dConvert::C0BSplineToC1BSplineCurve(...) and Geom2dConvert::C0BSplineToArrayOfC1BSplineCurve(...). Creation of test case for this issue. Adjusting test cases according to their new behavior. Small correction in the code according to KGV's remark.

0027766: Incorrect section curves between attached cylinders 2d-tolerance has been bounded above (earlier it was too big for precise computation). Creation of the test case for this issue. Adjusting some test cases according to their new behavior. Adjusting test case according to its new behavior.

0027310: Huge tolerance obtained in the result of intersection of two cylindrical faces Sometimes start point of the intersection line is in the surface boundary strictly. I.e. the parameter of this point in the surface can be equal to both 0 or 2*PI equivalently. It is important to chose correct parameter value. The algorithm of prediction is based on monotonicity property (see CylCylMonotonicity(...) function in IntPatch_ImpImpIntersection_4.gxx). Now, this function is used wrongly. The fix improves this situation. Small optimization in the code. Creation of test cases . The logic of returning value by the method BoundariesComputing() has been corrected.