0029807: [Regression to 7.0.0] Impossible to cut cone from prism
The algorithm has been improved for the cases when the intersection line goes through the cone apex.
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1. All special points are put to the ALine forcefully (if they are true intersection point). Currently this step has not been implemented yet.
2. Now the tolerance of IntPatch_Point (put into ALine) is computed in order to cover the distance between it and the correspond ALine.
3. Test cases have been created.
4. Procedure of trimming IntAna_Curve has been improved.
5. Criterion when the discriminant of IntAna_Curve can be considered to be equal to 0 has been improved.
6. Methods IntAna_Curve::FindParameter(...) (and IntPatch_ALine::FindParameter(...)) currently returns list of all parameters corresponding the given point (IntAna_Curve can be self-interfered curve). Before the fix, this method always returned only one (randomly chosen) parameter.
7. Interfaces of the following methods have been changed: IntAna_Curve::FindParameter(...), IntPatch_ALine::FindParameter(...), IntPatch_ALine::ChangeVertex(...), IntPatch_SpecialPoints::AddPointOnUorVIso(...), IntPatch_SpecialPoints::AddSingularPole(...), IntPatch_WLineTool::ExtendTwoWLines().
8. Following methods have been added: IntAna_Quadric::SpecialPoints(...), IntPatch_ALineToWLine::GetSectionRadius(...), IntPatch_SpecialPoints::ProcessSphere(...), IntPatch_SpecialPoints::ProcessCone(...), IntPatch_SpecialPoints::GetTangentToIntLineForCone(...).
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1) tests/boolean/volumemaker/C5
tests/boolean/volumemaker/C6
tests/boolean/volumemaker/E7
They are real IMPROVEMENTS. In the FIX (in compare with MASTER), section result between pairs of faces f2&f6 (C5), f3&f7 (C6) and f1&f5 (E7) is closed. Separated test cases have been created in order to focus on the problem with section. Bug #28503 has been fixed.
Correction in test cases.

- [DB] tests/bugs/modalg_7/bug29807_b4a