Return http.StatusNotFound error when trying to get a channel by name without permissions (#13443)

api4/channel.go

@@ -992,7 +992,7 @@ func getChannelByName(c *Context, w http.ResponseWriter, r *http.Request) {
 		}
 	} else {
 		if !c.App.SessionHasPermissionToChannel(c.App.Session, channel.Id, model.PERMISSION_READ_CHANNEL) {
-			c.SetPermissionError(model.PERMISSION_READ_CHANNEL)
+			c.Err = model.NewAppError("getChannelByName", store.MISSING_CHANNEL_ERROR, nil, "teamId="+channel.TeamId+", "+"name="+channel.Name+"", http.StatusNotFound)
 			return
 		}
 	}
@@ -1021,7 +1021,7 @@ func getChannelByNameForTeamName(c *Context, w http.ResponseWriter, r *http.Requ
 	}
 
 	if !c.App.SessionHasPermissionToChannel(c.App.Session, channel.Id, model.PERMISSION_READ_CHANNEL) {
-		c.SetPermissionError(model.PERMISSION_READ_CHANNEL)
+		c.Err = model.NewAppError("getChannelByNameForTeamName", store.MISSING_CHANNEL_ERROR, nil, "teamId="+channel.TeamId+", "+"name="+channel.Name+"", http.StatusNotFound)
 		return
 	}