Changing the Blog Create action to not try to add the blog slug to the blog slug constraint until after model state validation is verified.

--HG--
branch : dev

src/Orchard.Web/Modules/Orchard.Blogs/Controllers/BlogAdminController.cs

@@ -67,13 +67,14 @@ namespace Orchard.Blogs.Controllers {
 
             _blogService.Create(blog);
             model.Blog = _contentManager.UpdateEditorModel(blog, this);
-            _blogSlugConstraint.AddSlug(model.Blog.Item.Slug);
 
             if (!ModelState.IsValid) {
                 _transactionManager.Cancel();
                 return View(model);
             }
 
+            _blogSlugConstraint.AddSlug(model.Blog.Item.Slug);
+
             return Redirect(Url.BlogForAdmin(model.Blog.Item.Slug));
         }