"Remove Member" (Party and Guilds) appears to remove the wrong member - client-side display bug

[Alys]

When a Party or Guild leader removes a member from a Party or Guild, the member they select IS removed but the website initially shows that a different member was removed. When you reload, you see that only the selected member was removed.

Steps to reproduce:

1. Go to the Guild or Party and click on the "Member List" badge. (For a Party, you can also click the "View Party" button in the header.)
2. When the list of members appears, select one member that you want to remove.
3. (Optional) Take note of all the other members that appear on that screen. This is easiest in a small group of course.
4. Click on the three-dots button for that person and select "Remove Member".
5. Click the "Yes, remove them" button.
6. Observe that that person still appears in the list. This is part of the bug.
7. Observe that a different person has disappeared from the list. This is the other part of the bug.
8. Reload the website with your browser's refresh button.
9. Observe that that person you tried to remove is no longer in the list. This shows that it is only a client-side bug, not an API bug.
10. Observe that the different person who appeared to be incorrectly removed is still in the list (this is good).

Thanks to citrusella for reporting this. Below is her report with what she observed. The information above is what I observed when I confirmed it.

A strange issue with the party member modal, at least as clicked from the "view party" button in the header, when removing members: It always removed the bottommost member from the list (even if a different member was the one actually removed).

The first time I did this, it looked like it removed a different member and then removing the member I had originally intended to remove didn't work because they were no longer there (and the other member was missing from the modal). The second time this happened, it looked like I removed myself from the party, which caused a minor freakout on my part. It happened the same after a reload so I don't think it was exactly some sort of cache issue or anything (I reloaded to make sure the member modal was up-to-date after the first time, so I don't know if a sync would have fixed it). In both cases the intended member was the one actually removed and the different member disappearing from the list was purely a visual bug.

[airnyxx]

I tried to reproduce this bug on Linux in Chrome v88.0.4324.96, with no success. It may be a browser specific bug. Which browser and version are you reproducing the bug on?

[citrusella]

When I encountered the bug I was on Firefox 78 ESR on Windows 10. I can try seeing if I still encounter it, myself, though not right now...

[Alys]

It still happens for me. Firefox 85, Ubuntu.

[morganruffner]

Hi @Alys, I'm interested in working on this bug.

[morganruffner]

Hm I was not able to reproduce the bug on Chrome or Firefox on both MacOS and Ubuntu.

[Alys]

@morganruffner I'll leave this as "help wanted" for now since you can't reproduce it, but if you'd still like to investigate further and try to find a fix for it, please post again briefly and I'll mark it as in progress for you.

[Helcostr]

Do you have any relational information on "who" the other person is? And how many times that "removeMember" function has been called on the page prior to the visual bug?

Regardless, I would like to tackle this.

[citrusella]

Both times I did it, I had my citrustest account and an additional temporary test account in my party. IIRC every time I tried it my own citrusella account was at the top of the modal, so it's not simply removing someone from the end or anything. I'm pretty sure I kicked the highest in the list I wished to remove each time. It happened on the very first time I attempted to remove anyone from my party, not after I'd done it a few times. (For context, I'm in a party alone, so when I saw this happen it was only the two accounts that weren't my own I was working with.)