Fix parsing invalid strings

Author: shana

src/GitHub.Api/Primitives/TheVersion.cs

@@ -6,7 +6,7 @@ namespace GitHub.Unity
 {
     public struct TheVersion : IComparable<TheVersion>
     {
-        private const string versionRegex = @"(?<major>\d+)(\.?(?<minor>[^.]+))?(\.?(?<patch>[^.]+))?(\.?(?<build>.+))?";
+        private const string versionRegex = @"^(?<major>\d+)(\.?(?<minor>[^.]+))?(\.?(?<patch>[^.]+))?(\.?(?<build>.+))?";
         private const int PART_COUNT = 4;
         public static TheVersion Default { get; } = default(TheVersion).Initialize(null);
 

src/UnityExtension/Assets/Editor/UnityTests/VersionTests.cs

@@ -172,6 +172,10 @@ public void ComparisonWorks()
         version1 = TheVersion.Parse("0.33.3");
         version2 = TheVersion.Parse("0.33.3-beta");
         Assert.IsTrue(version1 > version2);
+
+        version1 = TheVersion.Parse("git version 2.11.1.windows.1");
+        version2 = TheVersion.Parse("2.17.0.windows.1");
+        Assert.IsTrue(version1 < version2);
     }
 
     [Test]
@@ -208,5 +212,7 @@ public void ParsingInvalidVersionStringsWorks()
         Assert.AreEqual(TheVersion.Default, ret);
         ret = TheVersion.Parse("bla");
         Assert.AreEqual(TheVersion.Default, ret);
+        ret = TheVersion.Parse("git version 2.11.1.windows.1");
+        Assert.AreEqual(TheVersion.Default, ret);
     }
 }