Apple's hyphenation API seems to behave odd, leading to suboptimal hyphenation in Safari and Chrome on Mac/iOS, see previous discussion at https://bugs.chromium.org/p/chromium/issues/detail?id=677263.
Blink maintainer kojii states:
OS X hyphenation API returns:
"infrastructure" -> "in-frastructure"
"frastructure" -> "fras-tructure"
"tructure" -> "truc-ture"
Attached a specific test case. Results:
Safari on Mac: "in-frastructure"
Firefox on Mac: "infrastruc-ture" (own dictionary)
Safari on Windows: "infrastruc-ture"
Created attachment 298181 [details]
Could you please file the bug via <https://bugreport.apple.com>? WebKit bugzilla is for WebKit bugs only, and while I can copy the bug for Apple, that would break the link to you as the reporter.
Ok, reported it over at bugreport.apple.com, ID 29944454.