Fix versionHeightOffset logic to use EffectiveVersionHeightOffset property

Co-authored-by: AArnott <[email protected]>

Author: Copilot

src/NerdBank.GitVersioning/LibGit2/LibGit2GitExtensions.cs

@@ -231,7 +231,7 @@ internal static Version GetIdAsVersionHelper(this Commit? commit, VersionOptions
         // and forbids 0xffff as a value.
         if (versionHeightPosition.HasValue)
         {
-            int adjustedVersionHeight = versionHeight == 0 ? 0 : versionHeight + (versionOptions?.VersionHeightOffset ?? 0);
+            int adjustedVersionHeight = versionHeight == 0 ? 0 : versionHeight + (versionOptions?.EffectiveVersionHeightOffset ?? 0);
             Verify.Operation(adjustedVersionHeight <= MaximumBuildNumberOrRevisionComponent, "Git height is {0}, which is greater than the maximum allowed {0}.", adjustedVersionHeight, MaximumBuildNumberOrRevisionComponent);
             switch (versionHeightPosition.Value)
             {
@@ -344,7 +344,7 @@ private static bool IsVersionHeightMismatch(Version version, VersionOptions vers
         {
             int expectedVersionHeight = SemanticVersion.ReadVersionPosition(version, position.Value);
 
-            int actualVersionOffset = versionOptions.VersionHeightOffsetOrDefault;
+            int actualVersionOffset = versionOptions.EffectiveVersionHeightOffset;
             int actualVersionHeight = GetCommitHeight(commit, tracker, c => CommitMatchesVersion(c, version, position.Value - 1, tracker));
             return expectedVersionHeight != actualVersionHeight + actualVersionOffset;
         }

src/NerdBank.GitVersioning/Managed/ManagedGitContext.cs

@@ -176,7 +176,7 @@ private Version GetIdAsVersionHelper(VersionOptions? versionOptions, int version
         // and forbids 0xffff as a value.
         if (versionHeightPosition.HasValue)
         {
-            int adjustedVersionHeight = versionHeight == 0 ? 0 : versionHeight + (versionOptions?.VersionHeightOffset ?? 0);
+            int adjustedVersionHeight = versionHeight == 0 ? 0 : versionHeight + (versionOptions?.EffectiveVersionHeightOffset ?? 0);
             Verify.Operation(adjustedVersionHeight <= MaximumBuildNumberOrRevisionComponent, "Git height is {0}, which is greater than the maximum allowed {0}.", adjustedVersionHeight, MaximumBuildNumberOrRevisionComponent);
             switch (versionHeightPosition.Value)
             {

src/NerdBank.GitVersioning/VersionOptions.cs

@@ -375,6 +375,38 @@ public int VersionHeightOffsetOrDefault
 #pragma warning restore CS0618
     }
 
+    /// <summary>
+    /// Gets the effective version height offset, taking into account the <see cref="VersionHeightOffsetAppliesTo"/> property.
+    /// </summary>
+    /// <returns>
+    /// The version height offset if it applies to the current version, or 0 if the version has changed
+    /// such that the offset should no longer be applied.
+    /// </returns>
+    [JsonIgnore]
+    public int EffectiveVersionHeightOffset
+    {
+        get
+        {
+            // Check if the offset applies to the current version
+            if (this.VersionHeightOffsetAppliesTo is object &&
+                this.Version is object &&
+                this.VersionHeightPosition.HasValue)
+            {
+                // If the version would be reset by a change from VersionHeightOffsetAppliesTo to Version,
+                // then the offset does not apply.
+                if (SemanticVersion.WillVersionChangeResetVersionHeight(
+                    this.VersionHeightOffsetAppliesTo,
+                    this.Version,
+                    this.VersionHeightPosition.Value))
+                {
+                    return 0;
+                }
+            }
+
+            return this.VersionHeightOffsetOrDefault;
+        }
+    }
+
     /// <summary>
     /// Gets or sets the version to which the <see cref="VersionHeightOffset"/> applies.
     /// When the <see cref="Version"/> property changes such that the version height would be reset,

src/NerdBank.GitVersioning/VersionOracle.cs

@@ -306,34 +306,7 @@ public string PrereleaseVersion
     /// when calculating the integer to use as the <see cref="BuildNumber"/>
     /// or elsewhere that the {height} macro is used.
     /// </summary>
-    public int VersionHeightOffset
-    {
-        get
-        {
-            if (this.VersionOptions is null)
-            {
-                return 0;
-            }
-
-            // Check if the offset applies to the current version
-            if (this.VersionOptions.VersionHeightOffsetAppliesTo is object &&
-                this.VersionOptions.Version is object &&
-                this.VersionOptions.VersionHeightPosition.HasValue)
-            {
-                // If the version would be reset by a change from VersionHeightOffsetAppliesTo to Version,
-                // then the offset does not apply.
-                if (SemanticVersion.WillVersionChangeResetVersionHeight(
-                    this.VersionOptions.VersionHeightOffsetAppliesTo,
-                    this.VersionOptions.Version,
-                    this.VersionOptions.VersionHeightPosition.Value))
-                {
-                    return 0;
-                }
-            }
-
-            return this.VersionOptions.VersionHeightOffsetOrDefault;
-        }
-    }
+    public int VersionHeightOffset => this.VersionOptions?.EffectiveVersionHeightOffset ?? 0;
 
     /// <summary>
     /// Gets or sets the ref (branch or tag) being built.