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Issue 645723 link

Starred by 3 users

Issue metadata

Status: Assigned
Owner:
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Windows
Pri: 3
Type: Bug-Regression



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Unicode "not identical to" character doesn't display properly

Reported by demi...@gmail.com, Sep 10 2016

Issue description

UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2856.0 Safari/537.36

Example URL:
https://en.wikipedia.org/wiki/Triple_bar

Steps to reproduce the problem:
1. Copy in adress bar "≢" character or open https://en.wikipedia.org/wiki/Triple_bar

What is the expected behavior?
Example image of how it should look properly can be found here http://www.fileformat.info/info/unicode/char/2262/index.htm

What went wrong?
See screenshot.

Does it occur on multiple sites: Yes

Is it a problem with a plugin? No 

Did this work before? Yes 

Does this work in other browsers? Yes 

Chrome version: 55.0.2856.0  Channel: n/a
OS Version: 10.0
Flash Version: 

This issue also affects newer builds of Atom text editor but on version 1.8 (released on June 7th) it was still displayed correctly.

Note, that there was recently fixed a similar issue https://bugs.chromium.org/p/chromium/issues/detail?id=641937 (Unicode dotted circle character does not combine properly with combining accents), but on most recent chromium build (rev 417796) this issue still remains.
 
not-identical-to-bug.png
457 bytes View Download

Comment 1 by kochi@chromium.org, Sep 12 2016

Cc: kochi@chromium.org behdad@chromium.org
Components: -Blink Blink>Fonts
Owner: drott@chromium.org
Status: Assigned (was: Unconfirmed)
Dominik, could you take a look at this?
Cc: rnimmagadda@chromium.org
Labels: -Type-Bug M-53 Type-Bug-Regression
====================================

Good Build:

40.0.2172.0    Base Position: 297115


Bad Build:

40.0.2214.0    Base Position: 303346

=====================================

Able to repro this issue only on Windows (Tested on 7 & 10) for the Google Chrome Stable Version - 53.0.2785.101

This is a regression issue broken in M55, below mentioned is the bisect info:

CHANGELOG URL: https://chromium.googlesource.com/chromium/src/+log/a91125d77bf01e9982fce536c95c5f213cf2413e..e53a64ea98335d39d00fc1ea1f32e86cd5a624cb

Thank you.

Comment 3 by drott@chromium.org, Sep 12 2016

Components: -Blink>Fonts UI
Owner: behdad@chromium.org
Behdad@, is HarfBuzz synthesizing this glyph? Trying with roettsch.es/≢.html the slash/strikethrough shows displayed in Times and in Arial and it looks synthesized. When I paste the character to WordPad it uses "Cambria Math".


Comment 4 by drott@chromium.org, Sep 12 2016

Cc: drott@chromium.org

Comment 5 by behdad@chromium.org, Sep 12 2016

The character is equivalent to U+2261 U+0338, so yes, harfbuzz tries that sequence as well.

Comment 6 by behdad@chromium.org, Sep 12 2016

So, essentially this is a font bug.

Comment 7 by drott@chromium.org, Sep 12 2016

Would it make sense for us to avoid/blacklist the attempt to use that sequence for the failing Windows fonts, Times New Roman and Arial?

Comment 8 by drott@chromium.org, Sep 12 2016

Labels: -Pri-2 Pri-3

Comment 9 by behdad@google.com, Sep 22 2016

We cannot really blacklist individual characters on individual fonts.  That would be too expensive.

Comment 10 by behdad@google.com, Jan 16 2018

Close this?  Don't think we'll do anything about it.
Please don't close this without at least providing a reference to what upstream library/module you feel is "responsible" for the underlying issue.  I've already tracked this issue upstream 2 hops (VSCode/Discord -> Electron -> Chromium).  Please don't make me chase this much further.

See also: https://github.com/Microsoft/vscode/issues/53816
See also: https://github.com/electron/electron/issues/13582

Is the upstream in this case "HarfBuzz", or is it a defect in someone's font definition(s)?
Assuming the answer is "yes it's HarfBuzz" I opened a ticket there:  https://github.com/harfbuzz/harfbuzz/issues/1092
At HarfBuzz we resolved it as a font missing-character issue.  Don't think there's anything to be done here (or there). Font rendering in the end relies on fonts having good character coverage, and Chrome does better than competition at finding a good font for a given syllable...
Labels: Hotlist-DesktopUIChecked Hotlist-DesktopUIValid
***Mass UI Triage***

This issue is still reproducible on Windows-10 using latest Canary version #72.0.3618.0.

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