Bug 180744

Summary: Narrow no-break space has no width on recent Safari and iOS
Product: WebKit Reporter: Emmanuel P <webkit>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: bfulgham, corsar89, icewil, mmaxfield, nico, simon.fraser, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: Safari 11   
Hardware: Unspecified   
OS: All   
URL: http://output.jsbin.com/rariyiwupa

Description Emmanuel P 2017-12-13 02:30:22 PST
Overview:
The narrow no-break space character (&#8239;) seems to have changed behavior in recent Safari versions. On macOS Sierra and High Sierra, with Safari 10.1 and 11 ; and on iOS 10 and 11, the character has no width at all. On previous versions, the character renders correctly.

Steps to Reproduce:
- Add narrow space characters in a HTML document via the HTML entity "&#8239;". You can go to the given jsbin link to see a test case.

Actual Results:
The narrow space is seemingly not rendered. Inspecting the page via the developer tools show no space at all.

Expected Results:
The narrow space should render.

Builds and Platforms:
The bug occurs on iOS 10 and 11, in Safari and in in-apps webviews.
The bug occurs on macOS Sierra with Safari 10.1.
The bug occurs on macOS High Sierra with Safari 11.

The bug does not occur on iOS 9.
The bug does not occur on macOS El Captain 9.1.

Additional Information:
Seemingly related bug: https://bugs.webkit.org/show_bug.cgi?id=172205. Difference is in my case the text is written in french.
I tried with multiple fonts including the -apple-system one without success.
Comment 1 Radar WebKit Bug Importer 2017-12-13 07:57:04 PST
<rdar://problem/36021002>