1223962 - AMO theme previews gets stuck in your browser UI, if you move cursor off of a theme snapshot in just the right way

Status: NEW

(Firefox :: Theme, defect)

Description

[Daniel Holbert [:dholbert]]

STR:
 1. Visit https://addons.mozilla.org/en-US/firefox/collections/mozmj/bold/
 2. Hover the top-left theme's preview-photo, until you see the preview appear in your browser UI.
 3. Move your mouse cursor down a bit, off of the bottom of the theme's photo. (over the theme's description)
 4. Now move your mouse cursor to the left, off of the theme entirely.

ACTUAL RESULTS:
Theme preview is stuck -- it stays applied in my browser UI, regardless of cursor-position, until I change tabs or hover a different theme.

EXPECTED RESULTS:
Theme preview should have been removed from browser UI as soon as I un-hovered the theme's photo.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug on a "Collections" page

Here's a screencast of the bug. Note that I get EXPECTED RESULTS if I move my cursor off the *top* of the theme's image (as shown later in the video) -- then, the theme gets un-applied immediately. But it gets stuck on if I move my cursor down over the description and then off to the side.

Comment 2

[Daniel Holbert [:dholbert]]

I can reproduce this in latest Firefox release (version 42) as well as latest Nightly (version 45.0a1 (2015-11-11)).

I'm pretty sure this is a website bug -- AMO presumably calls some javascript to apply & unapply the theme preview, and it must be failing to invoke the "unapply preview" javascript when I move my mouse off of the theme photo via this particular route.

Comment 3

[Daniel Holbert [:dholbert]]

This is easiest to reproduce on "collections" pages, since there's a blurb below each theme snapshot.  But I can reproduce it on other pages too -- e.g. I can reproduce it here...
 https://addons.mozilla.org/en-US/firefox/themes/
...if I hover the "Add" button briefly while I'm moving the cursor off of a theme image.

Basically, this seems to happen if I move the mouse across certain "neutral" areas on my way out of the image. (and these neutral areas include the "Add" button, and the theme description on Collections pages)

--> Changing component to Public Pages (not Collections) since this isn't Collections-specific.

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug on main Themes page (see comment 3)

Here's a screencast of this bug on the main Themes page, hovering (never clicking!) the "Add" button on my way out of a theme image.