Fix Guid.Empty instead of new Guid() (#632)

new Guid() generates a pre-filled Guid. Guid.Empty returns an empty Guid (full of zeros).

Author: labilbe

tests/ServiceStack.OrmLite.Tests/AutoIdTests.cs

@@ -32,8 +32,8 @@ public void Does_populate_and_return_new_guid_on_insert()
                 db.Insert(guidA);
                 db.Insert(guidB);
 
-                Assert.That(guidA.Id, Is.Not.EqualTo(new Guid()));
-                Assert.That(guidB.Id, Is.Not.EqualTo(new Guid()));
+                Assert.That(guidA.Id, Is.Not.EqualTo(Guid.Empty));
+                Assert.That(guidB.Id, Is.Not.EqualTo(Guid.Empty));
                 Assert.That(guidA.Id, Is.Not.EqualTo(guidB));
 
                 var dbA = db.SingleById<GuidAutoId>(guidA.Id);
@@ -57,8 +57,8 @@ public async Task Does_populate_and_return_new_guid_on_insert_Async()
                 await db.InsertAsync(guidA);
                 await db.InsertAsync(guidB);
 
-                Assert.That(guidA.Id, Is.Not.EqualTo(new Guid()));
-                Assert.That(guidB.Id, Is.Not.EqualTo(new Guid()));
+                Assert.That(guidA.Id, Is.Not.EqualTo(Guid.Empty));
+                Assert.That(guidB.Id, Is.Not.EqualTo(Guid.Empty));
                 Assert.That(guidA.Id, Is.Not.EqualTo(guidB));
 
                 var dbA = await db.SingleByIdAsync<GuidAutoId>(guidA.Id);
@@ -82,8 +82,8 @@ public void Does_populate_and_return_new_guid_on_save()
                 db.Save(guidA);
                 db.Save(guidB);
 
-                Assert.That(guidA.Id, Is.Not.EqualTo(new Guid()));
-                Assert.That(guidB.Id, Is.Not.EqualTo(new Guid()));
+                Assert.That(guidA.Id, Is.Not.EqualTo(Guid.Empty));
+                Assert.That(guidB.Id, Is.Not.EqualTo(Guid.Empty));
                 Assert.That(guidA.Id, Is.Not.EqualTo(guidB));
 
                 var dbA = db.SingleById<GuidAutoId>(guidA.Id);
@@ -107,8 +107,8 @@ public async Task Does_populate_and_return_new_guid_on_save_Async()
                 await db.SaveAsync(guidA);
                 await db.SaveAsync(guidB);
 
-                Assert.That(guidA.Id, Is.Not.EqualTo(new Guid()));
-                Assert.That(guidB.Id, Is.Not.EqualTo(new Guid()));
+                Assert.That(guidA.Id, Is.Not.EqualTo(Guid.Empty));
+                Assert.That(guidB.Id, Is.Not.EqualTo(Guid.Empty));
                 Assert.That(guidA.Id, Is.Not.EqualTo(guidB));
 
                 var dbA = await db.SingleByIdAsync<GuidAutoId>(guidA.Id);
@@ -161,4 +161,4 @@ public void Uses_existing_Guid_Id_if_not_Empty_for_row_inserts()
         }
     }
 
-}
+}