Bug 258962

Created attachment 466965 [details]
Offline HTML page sample test case

This may sound like bug #250987 / bug #250138, but it's not the exact same thing, because of one key difference: it manifests at normal (1.00) font scaling. It's more subtle / a potentially more rare occurrence though, so it was harder to spot compared to the other two bug reports.

The test case is the front page of https://themes.tiki.org

That website demonstrates that Epiphany 44.3 / WebKitGTK 2.40.3 renders fonts in an incompatible way that breaks layouts compared to Firefox 115 and Chromium 114, with default font scaling at 1.00x.

Since that website might change in the future, I'm attaching not only screenshots, but also an offline HTML version saved using Firefox; Epiphany seems able to open it.

As you can see in the attached screenshots, Epiphany renders all the fonts consistently fatter/bigger than other browsers. Firefox and Chromium render the font metrically identically among themselves, WebKitGTK is the outlier, and a ton of website layouts break in various ways when browsed with Epiphany. I was unable to find out why it renders differently in Epiphany vs the rest, given that my font settings are at the defaults. Enlarging the window width or shrinking the zoom level does nothing to improve results with the test case above.