[wpe-2.38] Incorrect rendering with flexbox layout

[filipe-norte-red]

The attached index.zip contains an example page using flexbox layout where the content is not correctly rendered:

Expected:

Actual:

Removing the "flex-direction" or "justify-content" properties in the "menu-title-container" style, causes the content to be correctly rendered (in the later case the content will not be centered when compared to the "expected" result above).

The attached example page renders as expected on Chrome and Firefox.

Internal reference: LLAMA-14257

[pgorszkowski-igalia]

The problem can also be reproduced on the latest WebKit. I will create an upstream report and investigate it there.