2049187 - Updated bookmarks sidebar panel: long titles overflow the panel and folders never show a tooltip

Status: RESOLVED FIXED

(Firefox :: Sidebar, defect, P3)

Description

[Gabriele Best [:Gabri]]

This bug tracks two related regressions in the updated bookmarks
sidebar panel introduced by bug 2019583. They share the same root
files and the same release-channel exposure, so they're filed
together.

Steps to reproduce

1. Set sidebar.revamp and sidebar.updatedBookmarks.enabled to
   true (the latter is the default on Nightly).
2. Open the bookmarks sidebar.
3. Make the sidebar narrow enough that long titles wouldn't fit on
   one line, or bookmark a page with a deliberately long title.

Actual behaviour
A. Bookmark and folder titles render in full and overflow the panel;
the row width exceeds the sidebar width and the text is painted
over the browser area. No ellipsis appears.
B. Hovering a folder (expanded <details><summary> or empty
<div class="bookmark-folder-label">) never shows a tooltip, even
when the title is cropped.
C. The OS default text I-beam cursor appears over the folder text
even though the element is clickable.

Expected behaviour
A. Titles should be truncated to the panel width using the standard
.text-truncated-ellipsis treatment (text-overflow: ellipsis).
B. Cropped folder titles should show a native tooltip with the full
title, matching the legacy XUL sidebar (tree.isCellCropped +
bhTooltip) and the URL rows in the new sidebar.
C. The cursor over folder rows should be a pointer.

Root cause

• sidebar-bookmark-list.css overrides the base fxview grid with
  grid-template-columns: unset on .fxview-tab-list and virtual-list,
  while every row/folder element still has grid-column: span 9.
  With no explicit columns those spans materialise as implicit
  auto-sized tracks that grow to max-content, so the rows expand to
  fit the text and text-overflow can never trigger.
• The compact rule in fxview-tab-row.css uses
  grid-template-columns: min-content auto. auto is essentially
  minmax(min-content, max-content), so the title column cannot
  shrink below its longest word, leaving long single words to
  overflow.
• SidebarBookmarkRow.tooltipText in sidebar-bookmark-list.mjs returns
  null when url is empty, so the title attribute is never set on
  folder-style rows. <summary> and .bookmark-folder-label have no
  tooltip wiring at all.
• details summary, .bookmark-folder-label have no cursor rule.
  While text was overflowing this was masked; once cropping is
  re-enabled the default text I-beam becomes visible.

Fix

• sidebar-bookmark-list.css: give both grid containers explicit
  shrinkable tracks (grid-template-columns: minmax(0, 1fr); grid-auto-columns: minmax(0, 1fr);). Add
  cursor: pointer; user-select: none; to
  details summary, .bookmark-folder-label.
• fxview-tab-row.css: in the compact row template, change the title
  column from auto to minmax(0, 1fr) so single long words can be
  truncated.
• sidebar-bookmark-list.mjs: add #updateFolderTooltip(e, title)
  that, on mouseenter, sets el.title = title when
  el.scrollWidth > el.clientWidth and removes the attribute
  otherwise. Wire @mouseenter on both the <summary> and the
  .bookmark-folder-label templates.

Notes

• Not visible on 151+ release/devedition/beta because
  sidebar.updatedBookmarks.enabled defaults to false there; in
  those channels the bookmarks sidebar still falls back to the
  legacy bookmarksSidebar.xhtml.
• Regression introduced when the file was first added (commit
  c207ea89352e — bug 2019583, Phabricator D288557, landed in
  151.0b1, March 2026).

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 2019583

Comment 2

[Gabriele Best [:Gabri]]

Attachment: Bug 2049187 - Sidebar bookmarks: truncate long titles and tooltip cropped folders r=#sidebar-reviewers,#fxview-reviewers

Comment 3

[Kelly Cochrane [:kcochrane]]

Ah I was testing with bookmark items, but I do see the issue with bookmark folders

Comment 4

[Kelly Cochrane [:kcochrane]]

Attachment: mac.png

Comment 5

[Gabriele Best [:Gabri]]

Attachment: sidebar.jpg

Before and after patch on Firefox 154 nightly build

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/05b27d47563b
https://hg.mozilla.org/integration/autoland/rev/1ae89413a03b
Sidebar bookmarks: truncate long titles and tooltip cropped folders r=fxview-reviewers,desktop-theme-reviewers,kcochrane

Comment 7

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/1ae89413a03b