1558063 - [Wayland] Popups are incorrectly scaled on HiDPI monitors

Status: RESOLVED DUPLICATE of bug 1420259

(Core :: Widget: Gtk, defect, P3)

Description

[jrkoenig]

Attachment: popup-scaling-firefox-wayland.png

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:67.0) Gecko/20100101 Firefox/67.0

Steps to reproduce:

Running Nightly on fractional scaling (150%) HiDPI monitor under GNOME wayland (GDK_BACKEND=wayland). Use menu items for a popup, or hover over a <img> with title attribute.

Versions:
Firefox Nightly 69.0a1 (2019-06-09) (64-bit) buildid: 20190609090758
Linux, Ubuntu 19.04
GNOME Shell 3.32.0

Actual results:

Popups from menu items and <img> title's are scaled incorrectly. The contents are scaled ~2x larger, but the dimensions of the popup are appropriately scaled so that the bottom and right of a popup are clipped, making some menu items unable to be selected with the mouse, or some title text unreadable. Mouse hovering correctly selects items according to their much larger size, so it isn't purely a rendering issue.

When the same window is dragged to a 1x scaling 1080p monitor, the popups are completely normal. The contents of webpages and the browser chrome (addressbar, etc) is correctly scaled. Only popups seem affected.

Expected results:

Popups should match the scaling of their underlying window and monitor and not be clipped.