Make regexes more strict

AssetRipper.Primitives.Tests/ParsingTests.cs

@@ -73,6 +73,22 @@ public void ShortChineseVersionFormat()
 		});
 	}
 
+	[TestCase("g2019")]
+	[TestCase("g2019.4")]
+	[TestCase("g2019.4.3")]
+	[TestCase("g2019.4.3f")]
+	[TestCase("g2019.4.3f1")]
+	[TestCase("g2019.4.3f1c1")]
+	[TestCase("2019g")]
+	[TestCase("2019.4g")]
+	[TestCase("2019.4.3g")]
+	[TestCase("2019.4.3fg")]
+	// "2019.4.3f1g" and "2019.4.3f1c1g" are technically valid because custom engines often append some text to the version string.
+	public void InvalidVersionStringFailsToParse(string versionString)
+	{
+		Assert.That(UnityVersion.TryParse(versionString, out _, out _), Is.False);
+	}
+
 	private static IEnumerable<UnityVersion> GenerateRandomVersions(int count)
 	{
 		Randomizer random = TestContext.CurrentContext.Random;

AssetRipper.Primitives/UnityVersionRegexes.cs

@@ -12,19 +12,19 @@ internal static partial class UnityVersionRegexes
 #endif
 
 	[StringSyntax("regex")]
-	private const string Major = @"([0-9]+)";
+	private const string Major = @"^([0-9]+)$";
 
 	[StringSyntax("regex")]
-	private const string MajorMinor = @"([0-9]+)\.([0-9]+)";
+	private const string MajorMinor = @"^([0-9]+)\.([0-9]+)$";
 
 	[StringSyntax("regex")]
-	private const string MajorMinorBuild = @"([0-9]+)\.([0-9]+)\.([0-9]+)";
+	private const string MajorMinorBuild = @"^([0-9]+)\.([0-9]+)\.([0-9]+)$";
 
 	[StringSyntax("regex")]
-	private const string Normal = @"([0-9]+)\.([0-9]+)\.([0-9]+)\.?([abcfpx])([0-9]+)((?:.|[\r\n])+)?";
+	private const string Normal = @"^([0-9]+)\.([0-9]+)\.([0-9]+)\.?([abcfpx])([0-9]+)((?:.|[\r\n])+)?$";
 
 	[StringSyntax("regex")]
-	private const string China = @"([0-9]+)\.([0-9]+)\.([0-9]+)\.?f1c([0-9]+)((?:.|[\r\n])+)?";
+	private const string China = @"^([0-9]+)\.([0-9]+)\.([0-9]+)\.?f1c([0-9]+)((?:.|[\r\n])+)?$";
 
 #if NET7_0_OR_GREATER
 	[GeneratedRegex(Major, Options)]