1158829 - On Firefox Mobile Unicode icons like 🔒 or 📌 suddenly require double linespace.

Status: UNCONFIRMED

(Core :: Graphics: Text, defect)

Description

[Kolya]

Attachment: Screenshot_2015-04-27-16-27-09.png

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:37.0) Gecko/20100101 Firefox/37.0
Build ID: 20150415140819
Firefox for Android

Steps to reproduce:

I created a website that uses some Unicode characters, such as: 🔒 or 📌 



Actual results:

It worked fine for the longest time until Firefox Mobile 37.0.2 (Android) came around.
Now these Unicode characters suddenly require double linespace. 

Test-page: https://www.systemshock.org/index.php?board=36.0;wap2


Expected results:

Being characters these Unicode icons should require as much line-height as any other character.

Comment 1

[Kevin Brosnan [Ex-Mozilla]]

This is not a regression. Using Android 5.1 the behavior is the same going back to Firefox 32 which is the oldest build of Firefox that will run on that version of Android. Suspect it might be a font issue.

Comment 2

[Kevin Brosnan [Ex-Mozilla]]

Fonts from the affected system, http://people.mozilla.org/~kbrosnan/tmp/1158829/n7-fonts.tar.bz2 Johnathan would you see if there is something odd with the glyphs?

Comment 3

[Jonathan Kew [:jfkthame]]

The font involved here would be Noto Color Emoji; but looking at the font data, I don't see any obvious reason it should result in this sort of excessive line spacing.

On my Android device (running 4.4.2) I don't see the issue; the lines with color-emoji glyphs do have slightly larger line height, but nowhere near the excessive spacing shown in the screenshot (attachment 8598022 [details]). My device has an older version of the Color Emoji font, but its line-spacing metrics are the same as yours, so it shouldn't behave any differently in this regard.

I wonder if it could be something about the version of FreeType present in Android 5.1? But I don't currently have a device where I can investigate/debug that.