1761668 - treeherder UX failure with long changeset description containing many bug links

Status: NEW

(Tree Management :: Treeherder: Frontend, defect)

Description

[Jonathan Kew [:jfkthame]]

See the treeherder view of mozilla-central changeset https://treeherder.mozilla.org/jobs?repo=mozilla-central&revision=4c6ce96f7492f2d1150af7b273acc3cdf7dd677d.

This is a merge from autoland that includes a backout changeset ee5983c94e61 with the description "Backed out 264 changesets (...list of 150+ bug numbers...)". Each bug number is supposed to be a link to bugzilla.

However, mousing over the bug numbers -- e.g. with the intention of clicking any of them -- shows a breakdown in the UI interaction. The cursor flickers rapidly between the default arrow cursor and the pointing finger that should appear when hovering a link, and the underline that these links are supposed to show when hovered also flickers rapidly on and off. Attempting to click any of the links does nothing. Attempting to drag-select any of the text (e.g. to copy/paste one of the bug numbers) also fails: much of the following text (including descriptions of other changesets and jobs) also gets highlighted, and it's impossible to select just the target range of text in this cset description.

Similar issues show up in Chrome; this doesn't appear to be a Firefox bug, but a failure of the treeherder UI.

Note that when a changeset description is hovered, treeherder shows a "tooltip" (not a native browser tooltip, I believe, but a dynamic element inserted in the page, probably absolute-positioned over the main content) with the bug title and cset summary. In the case of this backout cset, with such a long list of bugs, my guess is that it's trying to show an enormous tooltip that lists all these bugs, and this is breaking down (it never appears, in either Firefox or Chrome, though I did see one momentarily in Safari) and at the same time blocking normal interaction with the links or the text of the changeset summary.

I suspect, therefore, that some kind of clamping of the size of the tooltip that it tries to create might prevent this happening.