1 files changed, 253 insertions, 0 deletions

diff --git a/src/libs/WixToolset.Versioning/WixVersionComparer.cs b/src/libs/WixToolset.Versioning/WixVersionComparer.cs
new file mode 100644
index 00000000..be203634
--- /dev/null
+++ b/src/libs/WixToolset.Versioning/WixVersionComparer.cs
@@ -0,0 +1,253 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Versioning
+{
+    using System;
+    using System.Collections.Generic;
+
+    /// <summary>
+    /// WixVersion comparer.
+    /// </summary>
+    public class WixVersionComparer : IEqualityComparer<WixVersion>, IComparer<WixVersion>
+    {
+        /// <summary>
+        /// Default WixVersion comparer.
+        /// </summary>
+        public static readonly WixVersionComparer Default = new WixVersionComparer();
+
+        /// <inheritdoc />
+        public int Compare(WixVersion x, WixVersion y)
+        {
+            if ((object)x == y)
+            {
+                return 0;
+            }
+
+            if (x is null)
+            {
+                return -1;
+            }
+
+            if (y is null)
+            {
+                return 1;
+            }
+
+            var result = x.Major.CompareTo(y.Major);
+            if (result != 0)
+            {
+                return result;
+            }
+
+            result = x.Minor.CompareTo(y.Minor);
+            if (result != 0)
+            {
+                return result;
+            }
+
+            result = x.Patch.CompareTo(y.Patch);
+            if (result != 0)
+            {
+                return result;
+            }
+
+            result = x.Revision.CompareTo(y.Revision);
+            if (result != 0)
+            {
+                return result;
+            }
+
+            var xLabelCount = x.Labels?.Length ?? 0;
+            var yLabelCount = y.Labels?.Length ?? 0;
+            var maxLabelCount = Math.Max(xLabelCount, yLabelCount);
+
+            if (xLabelCount > 0)
+            {
+                if (yLabelCount == 0)
+                {
+                    return -1;
+                }
+            }
+            else if (yLabelCount > 0)
+            {
+                return 1;
+            }
+
+            for (var i = 0; i < maxLabelCount; ++i)
+            {
+                var xLabel = i < xLabelCount ? x.Labels[i] : null;
+                var yLabel = i < yLabelCount ? y.Labels[i] : null;
+
+                result = CompareReleaseLabel(xLabel, yLabel);
+                if (result != 0)
+                {
+                    return result;
+                }
+            }
+
+            var compareMetadata = false;
+
+            if (x.Invalid)
+            {
+                if (!y.Invalid)
+                {
+                    return -1;
+                }
+                else
+                {
+                    compareMetadata = true;
+                }
+            }
+            else if (y.Invalid)
+            {
+                return 1;
+            }
+
+            if (compareMetadata)
+            {
+                result = String.Compare(x.Metadata, y.Metadata, StringComparison.OrdinalIgnoreCase);
+            }
+
+            return (result == 0) ? 0 : (result < 0) ? -1 : 1;
+        }
+
+        /// <inheritdoc />
+        public bool Equals(WixVersion x, WixVersion y)
+        {
+            if ((object)x == y)
+            {
+                return true;
+            }
+
+            if (x is null)
+            {
+                return false;
+            }
+
+            if (y is null)
+            {
+                return false;
+            }
+
+            if (x.Major != y.Major)
+            {
+                return false;
+            }
+
+            if (x.Minor != y.Minor)
+            {
+                return false;
+            }
+
+            if (x.Patch != y.Patch)
+            {
+                return false;
+            }
+
+            if (x.Revision != y.Revision)
+            {
+                return false;
+            }
+
+            var labelCount = x.Labels?.Length ?? 0;
+            if (labelCount != (y.Labels?.Length ?? 0))
+            {
+                return false;
+            }
+
+            for (var i = 0; i < labelCount; ++i)
+            {
+                var result = CompareReleaseLabel(x.Labels[i], y.Labels[i]);
+                if (result != 0)
+                {
+                    return false;
+                }
+            }
+
+            if (x.Invalid)
+            {
+                if (y.Invalid)
+                {
+                    return String.Equals(x.Metadata, y.Metadata, StringComparison.OrdinalIgnoreCase);
+                }
+                else
+                {
+                    return false;
+                }
+            }
+            else if (y.Invalid)
+            {
+                return false;
+            }
+
+            return true;
+        }
+
+        /// <inheritdoc />
+        public int GetHashCode(WixVersion version)
+        {
+            var hash = 23L;
+            hash = hash * 37 + (version.Prefix ?? '\0');
+            hash = hash * 37 + version.Major;
+            hash = hash * 37 + version.Minor;
+            hash = hash * 37 + version.Patch;
+            hash = hash * 37 + version.Revision;
+            hash = hash * 37 + (version.Invalid ? 1 : 0);
+            hash = hash * 37 + (version.HasMajor ? 1 : 0);
+            hash = hash * 37 + (version.HasMinor ? 1 : 0);
+            hash = hash * 37 + (version.HasPatch ? 1 : 0);
+            hash = hash * 37 + (version.HasRevision ? 1 : 0);
+
+            if (version.Labels != null)
+            {
+                foreach (var label in version.Labels)
+                {
+                    hash = hash * 37 + label.Label.GetHashCode();
+                }
+            }
+
+            hash = hash * 37 + version.Metadata?.GetHashCode() ?? 0;
+
+            return unchecked((int)hash);
+        }
+
+        private static int CompareReleaseLabel(WixVersionLabel l1, WixVersionLabel l2)
+        {
+            if (l1 == l2)
+            {
+                return 0;
+            }
+            else if (l2 == null)
+            {
+                return 1;
+            }
+            else if (l1 == null)
+            {
+                return -1;
+            }
+
+            if (l1.Numeric.HasValue)
+            {
+                if (l2.Numeric.HasValue)
+                {
+                    return l1.Numeric.Value.CompareTo(l2.Numeric.Value);
+                }
+                else
+                {
+                    return -1;
+                }
+            }
+            else
+            {
+                if (l2.Numeric.HasValue)
+                {
+                    return 1;
+                }
+                else
+                {
+                    return String.Compare(l1.Label, l2.Label, StringComparison.OrdinalIgnoreCase);
+                }
+            }
+        }
+    }
+}