fix app open when multiple app providers are present (#2118)

changelog/unreleased/app-registry-multiple-providers.md

@@ -0,0 +1,7 @@
+Bugfix: Fix app open when multiple app providers are present
+
+We've fixed the gateway behavior, that when multiple app providers are present, it always returned that we have duplicate names for app providers.
+This was due the call to GetAllProviders() without any subsequent filtering by name. Now this filter mechanism is in place and the duplicate app providers error will only appear if a real duplicate is found.
+
+https://github.com/cs3org/reva/issues/2095
+https://github.com/cs3org/reva/pull/2117

internal/grpc/services/gateway/appprovider.go

@@ -283,15 +283,19 @@ func (s *svc) findAppProvider(ctx context.Context, ri *storageprovider.ResourceI
 		return nil, errtypes.InternalError("gateway: error finding app providers")
 	}
 
-	// if we only have one app provider we verify that it matches the requested app name
-	if len(res.Providers) == 1 {
-		p := res.Providers[0]
+	// as long as the above mentioned GetAppProviderByName(app) method is not available
+	// we need to apply a manual filter
+	filteredProviders := []*registry.ProviderInfo{}
+	for _, p := range res.Providers {
 		if p.Name == app {
-			return p, nil
+			filteredProviders = append(filteredProviders, p)
 		}
-		// we return error if we return the wrong app provider
-		err = errtypes.InternalError(fmt.Sprintf("gateway: user asked for app %q and we gave %q", app, p.Name))
-		return nil, err
+	}
+	res.Providers = filteredProviders
+
+	// if we only have one app provider we verify that it matches the requested app name
+	if len(res.Providers) == 1 {
+		return res.Providers[0], nil
 	}
 
 	// we should never arrive to the point of having more than one