1. In frame of the fix for #27282 issue, we have obtained several prolonged curves, which have common point(s). Fix for this issue joins these curves if it is possible.
2. ElCLib::InPeriod(...) method has been improved. Now it has become more faster (in general cases) and more reliable (in frame of FLT_OVERFLOW and DIVISION_BY_ZERO cases processing).
Creation of test case for issue #27302
Test case tests\bugs\modalg_6\bug27282_2 has been adjusted in accordance with its new behavior.
1. The reason of the regression is not-closed intersection result. This problem has been solved (in this fix) by adding joint point to the both neighbors intersection lines (lines were extended to the this intersection point). It is made in IntPatch_WLineTool::ExtendTwoWlinesToEachOther(...) method.
2. Interface of IntPatch_PointLine and inherited classes has been changed. Methods ChangeVertex(...) and RemoveVertex(...) have been added.
Test cases for this issue have been created.
Small correction in the code.