[Commenting] - adding new comment causes editor to go display blank content

[zeigerpuppy]

On testing of core-comments branch...

Have noticed issue, when adding new comment, the editor pane displays empty text content and markers on all lines.

To reproduce:

1. open document
2. select a portion of text
3. click on "Add comment" in comment pane - add comment and submit
4. The editor pane now shows a blank view with comment markers on each line

It doesn't look like content is lost.
In some cases, a force-reload brings the content back to a normal view. In other cases, the content can't be seen with a force-reload in the editor pane. The preview pane shows correct content.

No console error messages, looks like a rendering issue.

Also noticed in a document which I could reveal by reload, that a line break has been inserted in the editor before the comment anchor, even though there is no line break in text there.

[zeigerpuppy]

Interestingly, another way to recover the rendering failed condition is to reload the document in another account (shared workspace).

[MuNeNiCK]

I've addressed this in the core comments work.

The editor-side comment marker rendering no longer uses Monaco glyph-margin decorations for core comments. Those decorations were the likely source of the blank editor / marker-on-every-line rendering failure. Core comment markers are now rendered as one Monaco content widget per commented line, with grouped same-line comments handled by a single grouped marker.

I also changed the hidden markdown comment anchor rendering so the <!--comment:...--> anchor remains in the document model but has zero visual width in the editor. This avoids the extra visual spacing / apparent line break around anchors while still keeping the anchor in markdown.

I verified this with a browser E2E flow on the local app: create a document, select text, add a comment, confirm exactly one editor marker, confirm preview marker rendering, confirm the comment panel entry, and confirm the hidden anchor contributes zero layout width.

[zeigerpuppy]

Thanks @MuNeNiCK

I have tried the latest changes. The extra markers in the editor are gone.
However, now I don't see any markers at all in the editor pane and the line breaks around the comment anchor are still occurring for me.

Screenshot from Chromium:

Also noticed that if I edit the document, the text disappears at the end of the typing (I guess when comment markers should be re-rendering). The editor is also flickering, maybe re-rendering is breaking here?

[MuNeNiCK]

Thanks for retesting and for the screenshots.

I found that my previous follow-up was still too fragile. The editor-side marker rendering has now been reworked again:

• core comment markers are rendered through Monaco glyph-margin decorations, so they stay tied to editor lines instead of floating content widgets
• the hidden <!--comment:...--> anchor is handled as a separate inline decoration with explicit stickiness/letter-spacing handling
• comment decorations are rebuilt from the current Monaco model content after edits, so typing should no longer leave the raw anchor visible or cause the editor pane to blank/flicker
• newly created comments now use a compact marker id instead of a full UUID, which reduces line-wrap disruption around anchors

I verified this locally with browser E2E flows for both cases:

1. an existing long UUID-style comment anchor, then typing after it
2. creating a new comment through the UI and confirming the compact anchor, one editor marker, preview marker, and comment panel entry

I have this committed locally on the core-comments branch and will push it with the branch update once the remaining issue-level fixes are ready.