2 files changed, 11 insertions, 2 deletions

diff --git a/server/middlewares/activitypub.ts b/server/middlewares/activitypub.ts
index 12d5c22c5..d7f59be8c 100644
--- a/server/middlewares/activitypub.ts
+++ b/server/middlewares/activitypub.ts
@@ -18,7 +18,7 @@ async function checkSignature (req: Request, res: Response, next: NextFunction)
   try {
     actor = await getOrCreateActorAndServerAndModel(creator)
   } catch (err) {
-    logger.error('Cannot create remote actor and check signature.', { err })
+    logger.warn('Cannot create remote actor %s and check signature.', creator, { err })
     return res.sendStatus(403)
   }
 
diff --git a/server/middlewares/validators/video-channels.ts b/server/middlewares/validators/video-channels.ts
index 79587b028..56a347b39 100644
--- a/server/middlewares/validators/video-channels.ts
+++ b/server/middlewares/validators/video-channels.ts
@@ -14,6 +14,7 @@ import { UserModel } from '../../models/account/user'
 import { VideoChannelModel } from '../../models/video/video-channel'
 import { areValidationErrors } from './utils'
 import { isActorPreferredUsernameValid } from '../../helpers/custom-validators/activitypub/actor'
+import { ActorModel } from '../../models/activitypub/actor'
 
 const listVideoAccountChannelsValidator = [
   param('accountName').exists().withMessage('Should have a valid account name'),
@@ -34,11 +35,19 @@ const videoChannelsAddValidator = [
   body('description').optional().custom(isVideoChannelDescriptionValid).withMessage('Should have a valid description'),
   body('support').optional().custom(isVideoChannelSupportValid).withMessage('Should have a valid support text'),
 
-  (req: express.Request, res: express.Response, next: express.NextFunction) => {
+  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
     logger.debug('Checking videoChannelsAdd parameters', { parameters: req.body })
 
     if (areValidationErrors(req, res)) return
 
+    const actor = await ActorModel.loadLocalByName(req.body.name)
+    if (actor) {
+      res.status(409)
+         .send({ error: 'Another actor (account/channel) with this name on this instance already exists or has already existed.' })
+         .end()
+      return false
+    }
+
     return next()
   }
 ]