Fixed: Normalize unicode characters when comparing paths for equality

(cherry picked from commit ceeec091f85d0094e07537b7f62f18292655a710)

src/NzbDrone.Common.Test/PathExtensionFixture.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Text;
 using FluentAssertions;
 using Moq;
 using NUnit.Framework;
@@ -316,5 +317,14 @@ namespace NzbDrone.Common.Test
             result[2].Should().Be(@"Music");
             result[3].Should().Be(@"Artist Title");
         }
+
+        [Test]
+        public void should_be_equal_with_different_unicode_representations()
+        {
+            var path1 = @"C:\Test\file.mkv".AsOsAgnostic().Normalize(NormalizationForm.FormC);
+            var path2 = @"C:\Test\file.mkv".AsOsAgnostic().Normalize(NormalizationForm.FormD);
+
+            path1.PathEquals(path2);
+        }
     }
 }

src/NzbDrone.Common/Extensions/PathExtensions.cs

@@ -59,6 +59,10 @@ namespace NzbDrone.Common.Extensions
 
         public static bool PathEquals(this string firstPath, string secondPath, StringComparison? comparison = null)
         {
+            // Normalize paths to ensure unicode characters are represented the same way
+            firstPath = firstPath.Normalize();
+            secondPath = secondPath?.Normalize();
+
             if (!comparison.HasValue)
             {
                 comparison = DiskProviderBase.PathStringComparison;

src/NzbDrone.Common/PathEqualityComparer.cs

@@ -21,10 +21,10 @@ namespace NzbDrone.Common
         {
             if (OsInfo.IsWindows)
             {
-                return obj.CleanFilePath().ToLower().GetHashCode();
+                return obj.CleanFilePath().Normalize().ToLower().GetHashCode();
             }
 
-            return obj.CleanFilePath().GetHashCode();
+            return obj.CleanFilePath().Normalize().GetHashCode();
         }
     }
 }