Fix FileSystem.Combine when directory name is contained twice

Author: ky-one

Core.Common.Standard.Tests/KY.Core.Common.Standard.Tests.csproj

@@ -50,6 +50,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ObjectExtensionTests.cs" />
+    <Compile Include="PathHelperTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>

Core.Common.Standard.Tests/PathHelperTests.cs

@@ -0,0 +1,18 @@
+using KY.Core.DataAccess;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace KY.Core.Common.Standard.Tests
+{
+    [TestClass]
+    public class PathHelperTests
+    {
+        [TestMethod]
+        public void TestCombineWithRelativePathAndDuplicateDirectoryName()
+        {
+            PathHelper pathHelper = new PathHelper();
+            string result = pathHelper.Combine(@"C:\One\Two\Three\Two", "../Four");
+            Assert.AreEqual(@"C:\One\Two\Three\Four", result);
+        }
+        
+    }
+}

Core.Common.Standard/DataAccess/PathHelper.cs

@@ -18,6 +18,7 @@ public class PathHelper
         private static readonly Regex absolutePathRegex = RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
                                                               ? new Regex(@"^(([A-z]:)|(file:\\\\)|(\\\\))")
                                                               : new Regex("^/");
+
         public string Root { get; }
 
         public PathHelper(string root = null)
@@ -98,10 +99,10 @@ public string Combine(params string[] pathChunks)
                         }
                         else if (isDrive && parts.Count > 1 || !isDrive && parts.Count > 0)
                         {
-                            parts.Remove(last);
+                            parts.RemoveAt(parts.Count - 1);
                         }
                     }
-                    else if (parts.Count == 0 ||last == parentSymbol)
+                    else if (parts.Count == 0 || last == parentSymbol)
                     {
                         parts.Add(chunk);
                     }

Core.Common.Standard/KY.Core.Common.Standard.csproj

@@ -4,7 +4,7 @@
     <TargetFramework>netstandard2.0</TargetFramework>
     <RootNamespace>KY.Core</RootNamespace>
     <AssemblyName>KY.Core.Common</AssemblyName>
-    <Version>4.17.0</Version>
+    <Version>4.18.0</Version>
     <Authors>KY-Programming</Authors>
     <Company>KY-Programmingp</Company>
     <Product>KY.Core</Product>