Merge pull request #123 from github/nullref

Fix potential NullReferenceExceptions

Author: shana

src/DesignTimeStyleHelper/App.xaml.cs

@@ -110,12 +110,12 @@ T Create<T>() where T : class
             return new Mock<T>().Object;
         }
 
-        object Create(Type t)
+        static object Create(Type t)
         {
             var moq = typeof(Mock<>).MakeGenericType(t);
             var ctor = moq.GetConstructor(new Type[] { });
-            var m = ctor.Invoke(new object[] { }) as Mock;
-            return m.Object;
+            var m = ctor?.Invoke(new object[] { }) as Mock;
+            return m?.Object;
         }
 
         public ExportProvider DefaultExportProvider { get; set; }

src/GitHub.Exports/Primitives/HostAddress.cs

@@ -98,7 +98,7 @@ public override bool Equals(object obj)
             if (ReferenceEquals(this, obj))
                 return true;
             var other = obj as HostAddress;
-            return obj != null && WebUri.IsSameHost(other.WebUri) && ApiUri.IsSameHost(other.ApiUri);
+            return other != null && WebUri.IsSameHost(other.WebUri) && ApiUri.IsSameHost(other.ApiUri);
         }
     }
 }