AssemblyNameReference.Version should never return null. Fixes #212

4 files changed, 27 insertions, 12 deletions

diff --git a/Mono.Cecil/AssemblyNameReference.cs b/Mono.Cecil/AssemblyNameReference.cs
index c61c336..3a9858f 100644
--- a/Mono.Cecil/AssemblyNameReference.cs
+++ b/Mono.Cecil/AssemblyNameReference.cs
@@ -49,8 +49,8 @@ namespace Mono.Cecil {
 		public Version Version {
 			get { return version; }
 			set {
-				 version = value;
-				 full_name = null;
+				version = value ?? Mixin.ZeroVersion;
+				full_name = null;
 			}
 		}
 
@@ -147,11 +147,9 @@ namespace Mono.Cecil {
 
 				var builder = new StringBuilder ();
 				builder.Append (name);
-				if (version != null) {
-					builder.Append (sep);
-					builder.Append ("Version=");
-					builder.Append (version.ToString ());
-				}
+				builder.Append (sep);
+				builder.Append ("Version=");
+				builder.Append (Version.ToString (fieldCount: 4));
 				builder.Append (sep);
 				builder.Append ("Culture=");
 				builder.Append (string.IsNullOrEmpty (culture) ? "neutral" : culture);
@@ -239,7 +237,7 @@ namespace Mono.Cecil {
 				throw new ArgumentNullException ("name");
 
 			this.name = name;
-			this.version = version;
+			this.version = version ?? Mixin.ZeroVersion;
 			this.hash_algorithm = AssemblyHashAlgorithm.None;
 			this.token = new MetadataToken (TokenType.AssemblyRef);
 		}
@@ -249,4 +247,9 @@ namespace Mono.Cecil {
 			return this.FullName;
 		}
 	}
+
+	partial class Mixin {
+
+		public static Version ZeroVersion = new Version (0, 0, 0 ,0);
+	}
 }
diff --git a/Mono.Cecil/BaseAssemblyResolver.cs b/Mono.Cecil/BaseAssemblyResolver.cs
index 8a11182..76f5da1 100644
--- a/Mono.Cecil/BaseAssemblyResolver.cs
+++ b/Mono.Cecil/BaseAssemblyResolver.cs
@@ -134,7 +134,7 @@ namespace Mono.Cecil {
 #if !SILVERLIGHT && !CF
 			if (name.IsRetargetable) {
 				// if the reference is retargetable, zero it
-				name = new AssemblyNameReference (name.Name, new Version (0, 0, 0, 0)) {
+				name = new AssemblyNameReference (name.Name, Mixin.ZeroVersion) {
 					PublicKeyToken = Empty<byte>.Array,
 				};
 			}
@@ -187,7 +187,7 @@ namespace Mono.Cecil {
 
 		static bool IsZero (Version version)
 		{
-			return version == null || (version.Major == 0 && version.Minor == 0 && version.Build == 0 && version.Revision == 0);
+			return version.Major == 0 && version.Minor == 0 && version.Build == 0 && version.Revision == 0;
 		}
 
 #if !SILVERLIGHT && !CF
diff --git a/Mono.Cecil/ModuleDefinition.cs b/Mono.Cecil/ModuleDefinition.cs
index f887789..26534df 100644
--- a/Mono.Cecil/ModuleDefinition.cs
+++ b/Mono.Cecil/ModuleDefinition.cs
@@ -967,7 +967,7 @@ namespace Mono.Cecil {
 			if (name.EndsWith (".dll") || name.EndsWith (".exe"))
 				name = name.Substring (0, name.Length - 4);
 
-			return new AssemblyNameDefinition (name, new Version (0, 0, 0, 0));
+			return new AssemblyNameDefinition (name, Mixin.ZeroVersion);
 		}
 
 #endif
diff --git a/Test/Mono.Cecil.Tests/AssemblyTests.cs b/Test/Mono.Cecil.Tests/AssemblyTests.cs
index 7ba3dda..b427f5c 100644
--- a/Test/Mono.Cecil.Tests/AssemblyTests.cs
+++ b/Test/Mono.Cecil.Tests/AssemblyTests.cs
@@ -25,7 +25,7 @@ namespace Mono.Cecil.Tests {
 		}
 
 		[Test]
-		public void ParseLowerCaseNameParts()
+		public void ParseLowerCaseNameParts ()
 		{
 			var name = AssemblyNameReference.Parse ("Foo, version=2.0.0.0, culture=fr-FR");
 			Assert.AreEqual ("Foo", name.Name);
@@ -33,5 +33,17 @@ namespace Mono.Cecil.Tests {
 			Assert.AreEqual (0, name.Version.Minor);
 			Assert.AreEqual ("fr-FR", name.Culture);
 		}
+
+		[Test]
+		public void ZeroVersion ()
+		{
+			var name = new AssemblyNameReference ("Foo", null);
+			Assert.AreEqual ("0.0.0.0", name.Version.ToString (fieldCount: 4));
+			Assert.AreEqual ("Foo, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null", name.FullName);
+
+			name = new AssemblyNameReference ("Foo", new Version (0, 0, 0, 0));
+			Assert.AreEqual ("0.0.0.0", name.Version.ToString (fieldCount: 4));
+			Assert.AreEqual ("Foo, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null", name.FullName);
+		}
 	}
 }