Reproducible phantom spaces are rendered using custom font

• Component: Layout and Rendering
• Status: NEW ---

[Xiaodi Wu]

Created attachment 335543 [details]
Screenshot of errant space highlighted

The same rendering issue does not occur using Chrome on the same machine.

When CSS is enabled (under the "Develop" menu), some confluence of events causes Safari to render what appears to be an extra space, which is not present in the markup. The space can be highlighted, but Safari appears to think that the highlighted text is in fact the following glyph. Every subsequent glyph in the remainder of the line appears to be offset in relation to its highlight. This issue disappears upon disabling CSS, but reliably reappears in the same spot after re-enabling CSS.

Attached is a screenshot of the relevant behavior.

The URL for the document is (at present):
https://numerics.diploid.ca/floating-point-part-1.html

The relevant custom fonts are Source Sans Pro and, for monospace not used in that line, Inconsolata; both are loaded from Google Fonts.

Expected behavior:
Correct rendering of the text, with glyphs not offset from the highlight.

[Radar WebKit Bug Importer]

<rdar://problem/38359762>