1521846 - Hyphenated ligatures display wrong

Status: RESOLVED DUPLICATE of bug 479829

(Core :: Graphics: Text, defect)

Description

[Mark Roberts]

Attachment: bug.html

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0

Steps to reproduce:

Layout text to be hyphenated, make the box narrow enough to actually force hyphenation, use words with lots of lower-case double F's.

Actual results:

Double F's are displayed as ligatures. Whenever a hyphen goes between two F's, Firefox splits the ligature over two lines, displaying part of the first F at the beginning of the next line.

Expected results:

If hyphenation occurs, two individual F characters should be used, not the first and second half of a double-F-ligature.

Comment 1

[Mark Roberts]

Visibility of the error depends on the font used. In Firefox 60 on my Debian/GNU Linux 9 the following apply:

No font-family set: /* error visible */
font-family: serif; /* error visible */
font-family: sans; /* error visible */
font-family: arial; /* error not visible */

Comment 2

[Mark Roberts]

Attachment: Screenshot of correct versus buggy display

Comment 3

[Jonathan Kew [:jfkthame]]

This is a known issue. Currently, text shaping (including things like ligatures) occurs before line-breaking (which it must, in order to measure the shaped text); but we don't re-shape after breaking the line.