Handle invariant culture in RedirectTrackingHandler

GetRouteById and RedirectUrlService expects the culture to be null if it's invariant, however, Cultures in IPublished content uses empty string for invariant culture

Author: nikolajlauridsen

src/Umbraco.Infrastructure/Routing/RedirectTrackingHandler.cs

@@ -99,25 +99,33 @@ private void StoreOldRoute(IContent entity, OldRoutesDictionary oldRoutes)
             {
                 return;
             }
-            var contentCache = publishedSnapshot.Content;
-            var entityContent = contentCache?.GetById(entity.Id);
+
+            IPublishedContentCache contentCache = publishedSnapshot.Content;
+            IPublishedContent entityContent = contentCache?.GetById(entity.Id);
             if (entityContent == null)
+            {
                 return;
+            }
 
             // get the default affected cultures by going up the tree until we find the first culture variant entity (default to no cultures)
             var defaultCultures = entityContent.AncestorsOrSelf()?.FirstOrDefault(a => a.Cultures.Any())?.Cultures.Keys.ToArray()
                 ?? new[] { (string)null };
-            foreach (var x in entityContent.DescendantsOrSelf(_variationContextAccessor))
+
+            foreach (IPublishedContent publishedContent in entityContent.DescendantsOrSelf(_variationContextAccessor))
             {
                 // if this entity defines specific cultures, use those instead of the default ones
-                var cultures = x.Cultures.Any() ? x.Cultures.Keys : defaultCultures;
+                IEnumerable<string> cultures = publishedContent.Cultures.Any() ? publishedContent.Cultures.Keys : defaultCultures;
 
                 foreach (var culture in cultures)
                 {
-                    var route = contentCache.GetRouteById(x.Id, culture);
+                    var checkedCulture = string.IsNullOrEmpty(culture) ? null : culture;
+                    var route = contentCache.GetRouteById(publishedContent.Id, checkedCulture);
                     if (IsNotRoute(route))
+                    {
                         continue;
-                    oldRoutes[new ContentIdAndCulture(x.Id, culture)] = new ContentKeyAndOldRoute(x.Key, route);
+                    }
+
+                    oldRoutes[new ContentIdAndCulture(publishedContent.Id, culture)] = new ContentKeyAndOldRoute(publishedContent.Key, route);
                 }
             }
         }
@@ -135,14 +143,18 @@ private void CreateRedirects(OldRoutesDictionary oldRoutes)
             {
                 _logger.LogWarning("Could not track redirects because there is no current published snapshot available.");
                 return;
-            } 
+            }
 
-            foreach (var oldRoute in oldRoutes)
+            foreach (KeyValuePair<ContentIdAndCulture, ContentKeyAndOldRoute> oldRoute in oldRoutes)
             {
-                var newRoute = contentCache.GetRouteById(oldRoute.Key.ContentId, oldRoute.Key.Culture);
+                var culture = string.IsNullOrWhiteSpace(oldRoute.Key.Culture) ? null : oldRoute.Key.Culture;
+                var newRoute = contentCache.GetRouteById(oldRoute.Key.ContentId, culture);
                 if (IsNotRoute(newRoute) || oldRoute.Value.OldRoute == newRoute)
+                {
                     continue;
-                _redirectUrlService.Register(oldRoute.Value.OldRoute, oldRoute.Value.ContentKey, oldRoute.Key.Culture);
+                }
+
+                _redirectUrlService.Register(oldRoute.Value.OldRoute, oldRoute.Value.ContentKey, culture);
             }
         }