If channels are created with a certain arrangement of characters, the channel appears twice



When a channel is created with a certain combination of characters (including special characters), the created channel will be shown in both the channels list and the direct messages list


Tested in the following :

  • Mattermost 5.19.1

  • Mattermost 5.17.1

  • Mattermost 5.20.2

  • Mattermost 5.21.0

Steps to reproduce

Create a channel with the following combination of characters - 10 characters<space>9 characters<space>dash<space>9 characters<space>7 characters

For example, a 10 character word - additional
Followed by a 9 character word - abilities
Then another 9 character word - community
And finally a 7 character word - systems

The resulting channel name will be something like this :

Expected behavior

The channel will be created as per usual and only appear in the list of channels

Actual behavior

It appears in both the channel list and direct messages :


  • Whether or not caps are used does not seem to affect it

  • The dash has to be present for the behavior to happen

  • Changing the name or the URL of the channel after it is created (and shows up in both places) doesn't change the behavior

  • Right now this is the only number of characters that I can confirm is causing the issue, from my tests, removing or adding one of 2 characters when creating the channel causes the behavior to not happen

QA Test Steps

Please also cover a test case where you have a channel with this issue in 5.19.1, then upgrade to 5.19.2. Need to confirm if the preferences also need to be cleared after the upgrade, or if the upgrade will handle it itself. (Can ask Farhan for more details)

  • Create a public channel with the name `additional abilities - community systems` or any other 40 character name

  • Ensure that it does not show in the direct messages list

  • Create a group message channel and ensure that it shows up in the direct messages list

  • Create a direct message and ensure that it shows up in the direct messages list


Rohitesh Gupta
April 20, 2020, 1:48 PM

The upgrade from 5.19.1 to 5.19.2-rc1 was also tested and the channel with length=40 was no longer displayed under the Direct Messages. The issue is fixed on 5.19.2-rc1 and is working fine.

Rohitesh Gupta
April 16, 2020, 4:29 PM

Tested on the 5.19.2-rc1 and the issue is fixed on 5.19 and is working fine.

Rohitesh Gupta
April 6, 2020, 1:18 PM

Tested on the latest 5.22 RC test instance and the issue is working fine as expected. Closing the ticket.

Farhan Munshi
March 20, 2020, 7:36 PM

Yea sure given the fact that I already have a PR opened its just a matter of getting it through QA in time

Eric Sethna
March 20, 2020, 7:35 PM






Farhan Munshi

QA Assignee

Rohitesh Gupta


Joe Wai Tye

Epic Link


Fix versions

Mattermost Team

Sustained Engineering




QA Testing Areas


GitHub Issue