Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/KernelWrappers/MacroStabilityCommon/MacroStabilityCommonHelperTests.cs
===================================================================
diff -u -r4991 -r4992
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/KernelWrappers/MacroStabilityCommon/MacroStabilityCommonHelperTests.cs	(.../MacroStabilityCommonHelperTests.cs)	(revision 4991)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/KernelWrappers/MacroStabilityCommon/MacroStabilityCommonHelperTests.cs	(.../MacroStabilityCommonHelperTests.cs)	(revision 4992)
@@ -61,4 +61,38 @@
             Assert.That(geometry.SurfaceLine.Points.Last().Z, Is.EqualTo(0.0).Within(cTolerance));
         });
     }
+
+    [Test]
+    public void GivenSoilGeometryProbabilityWithSoilProfile2DAndMatchingSurfaceLineWhenCombiningThenSoilProfile2DIsUnchanged()
+    {
+        SoilGeometryProbability soilGeometryProbability = CreateSoilGeometryProbabilityWithSoilProfile2DWithSurfaceLineDitchDike();
+        // Create the same surfaceline as is used for creating the SoilProfile2D in the SoilGeometryProbability
+        SurfaceLine2 surfaceLine = FactoryForSurfaceLines.CreateSurfaceLineWithDikeAndDitch();
+        // Now combine the soilGeometryProbability with the same SurfaceLine2 which should result in the same SoilProfile2D
+        MacroStabilityCommonHelper.CombineSoilProfileWithSurfaceLine(soilGeometryProbability, surfaceLine, new Soil());
+        GeometryData geometry = soilGeometryProbability.SoilProfile2D.Geometry;
+        // For debugging purposes
+        // GeometryExporter.ExportToFile(geometry, visualizationFolder + "Geometry.txt");
+        // GeometryExporter.ExportToJsonFile(geometry, visualizationFolder + "Geometry.json");
+        Assert.Multiple(() =>
+        {
+            Assert.That(soilGeometryProbability.SoilProfileType, Is.EqualTo(SoilProfileType.ProfileType2D));
+            Assert.That(geometry.Surfaces, Has.Count.EqualTo(1));
+            Assert.That(geometry.Left, Is.EqualTo(0.0).Within(cTolerance));
+            Assert.That(geometry.Right, Is.EqualTo(75.0).Within(cTolerance));
+            Assert.That(geometry.Bottom, Is.EqualTo(-20.0).Within(cTolerance));
+            Assert.That(geometry.SurfaceLine.Points.First().X, Is.EqualTo(0.0).Within(cTolerance));
+            Assert.That(geometry.SurfaceLine.Points.First().Z, Is.EqualTo(0.0).Within(cTolerance));
+            Assert.That(geometry.SurfaceLine.Points.Last().X, Is.EqualTo(75.0).Within(cTolerance));
+            Assert.That(geometry.SurfaceLine.Points.Last().Z, Is.EqualTo(0.0).Within(cTolerance));
+        });
+    }
+
+    private SoilGeometryProbability CreateSoilGeometryProbabilityWithSoilProfile2DWithSurfaceLineDitchDike()
+    {
+        SoilGeometryProbability soilGeometryProbability = FactoryForSoilGeometryProbabilities.CreateSoilGeometryProbabilityWithSoilProfile1D();
+        SurfaceLine2 surfaceLine = FactoryForSurfaceLines.CreateSurfaceLineWithDikeAndDitch();
+        MacroStabilityCommonHelper.CombineSoilProfileWithSurfaceLine(soilGeometryProbability, surfaceLine, new Soil());
+        return soilGeometryProbability;
+    }
 }
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