Publishing alias requires it both be taken and not, becoming impossible

Steps to reproduce

1. attempt to publish an alternate room alias

Outcome

What did you expect?

Alternate alias should submit as-entered

What happened instead?

According to the synapse logs, Element is attempting to query for the alias with an extra “#” on the front, causing an error that leaves it unable to publish the alias.

Synapse (1.50.2) log:

Feb 01 06:11:56 synapse[184312]: 2022-02-01 06:11:56,220 - root - 262 - WARNING - GET-236997 - Error retrieving alias
Feb 01 06:11:56 synapse[184312]: 2022-02-01 06:11:56,220 - synapse.http.server - 95 - INFO - GET-236997 - <XForwardedForRequest at 0x7fdb20704400 method='GET' uri='/_matrix/client/r0/directory/room/%23%23testingalias456%3Amatrix.org' clientproto='HTTP/1.0' site='8008'> SynapseError: 404 - Room alias ##testingalias456:matrix.org not found
Feb 01 06:11:56 synapse[184312]: 2022-02-01 06:11:56,224 - synapse.http.matrixfederationclient - 607 - INFO - GET-236998 - {GET-O-256879} [matrix.org] Got response headers: 404 Not Found

Attempting to exclude the “#” at the front doesn’t work:

Operating system

Arch Linux

Browser information

Firefox 96

URL for webapp

develop.element.io

Application version

Element version: d731a2561933-react-afe6021c9a06-js-51f3fac87be4 Olm version: 3.2.8

Homeserver

private instance, but was able to replicate client-side error with matrix.org

Will you send logs?

No

[t3chguy]

Yup, can reproduce, this field is checking the alias is unused which is backwards to what the field needs

[BurnyBoi]

It worked there as well. I just looked inside matrix-react-sdk in my node_modules and it looks like yarn still provided me 3.39.0 rather than 3.39.1, even on a fresh pull and run of yarn. That explains why I still don’t have it. I guess I could either try to force it to pull the newer one or just wait until I get it naturally.