Add missing hyphen before commit ID in semver 1 property

Fixes #273

Author: AArnott

src/NerdBank.GitVersioning.Tests/VersionOracleTests.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Text.RegularExpressions;
 using LibGit2Sharp;
 using Nerdbank.GitVersioning;
 using Nerdbank.GitVersioning.Tests;
@@ -162,6 +163,22 @@ public void SemVer1PrereleaseConversionPadding()
         Assert.Equal("7.8.9-foo-025", oracle.SemVer1);
     }
 
+    [Fact]
+    public void SemVerStableNonPublicVersion()
+    {
+        var workingCopyVersion = new VersionOptions
+        {
+            Version = SemanticVersion.Parse("2.3"),
+        };
+        this.WriteVersionFile(workingCopyVersion);
+        this.InitializeSourceControl();
+        var oracle = VersionOracle.Create(this.RepoPath);
+        oracle.PublicRelease = false;
+        Assert.True(Regex.IsMatch(oracle.SemVer1, @"^2.3.1-[^g]{10}$"));
+        Assert.True(Regex.IsMatch(oracle.SemVer2, @"^2.3.1-[^g]{10}$"));
+        Assert.True(Regex.IsMatch(oracle.NuGetPackageVersion, @"^2.3.1-g[a-f0-9]{10}$"));
+    }
+
     [Fact]
     public void DefaultNuGetPackageVersionIsSemVer1PublicRelease()
     {

src/NerdBank.GitVersioning/VersionOracle.cs

@@ -377,7 +377,7 @@ public IDictionary<string, string> CloudBuildVersionVars
         /// Gets the build metadata, compliant to SemVer 1.0.
         /// </summary>
         private string SemVer1BuildMetadata =>
-            this.PublicRelease ? string.Empty : this.GitCommitIdShort;
+            this.PublicRelease ? string.Empty : $"-{this.GitCommitIdShort}";
 
         /// <summary>
         /// Gets a SemVer 1.0 compliant string that represents this version, including the -gCOMMITID suffix