fix: rich workspaces overlap with new file dropdown

[gary-kim]

Fix https://github.com/nextcloud/server/issues/27588

• Target version: master

Before

After

[gary-kim]

Rebased

[gary-kim]

@juliushaertl Could you take a look when you have time? Thanks.

[szaimen]

/rebase

[szaimen]

/compile amend /

[juliusknorr]

Mind to drop the comment above since with the removed IE11 support this is no longer required and caused side effects the bug the pr fixes ;)

[gary-kim]

Done

[juliusknorr]

Sorry for taking so long for the review, I have a small comment, but tested and works fine otherwise 👍

[szaimen]

I wonder what the difference to this PR is: #1631

[juliusknorr]

The position: unset; that is currently set on #editor-wrapper basically moves the element into the regular stacking context and will be above any element due to its order in the dom. Since the #editor has 10000 (which is adjusted in this PR), the 10000 are in the regular stacking context. The other PR creates a new stacking context (which would have an implicit z-index of 0 as non is set on that element) so the 10000 no longer are taken into the global but the local stacking context of the parent only.

https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Positioning/Understanding_z_index/Stacking_without_z-index and
https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Positioning/Understanding_z_index/The_stacking_context might be a good first read on the topics.

The second PR would be a good possible addition to avoid further overlay issues, but I need to do some further testing on that.

[juliusknorr]

/backport to stable22

[backportbot-nextcloud]

The backport to stable22 failed. Please do this backport manually.

[szaimen]

Created the backport manually in #1769

[szaimen]

/backport to stable21

[backportbot-nextcloud]

The backport to stable21 failed. Please do this backport manually.

[szaimen]

Created the backport manually in #1770