[@font-face] (Unicode mapping, glyph index) : A font applied via <font tag, display different characters when applied via @font-face




Layout: Text
7 years ago
3 years ago


(Reporter: Roberto Bouzout (tito), Unassigned)


5 Branch

Firefox Tracking Flags

(Not tracked)



(4 attachments)



7 years ago
User-Agent:       Mozilla/5.0 (Windows NT 5.1; rv:5.0) Gecko/20100101 Firefox/5.0
Build Identifier: 

Technical explanation from a user:

@font-face picks characters out of the Bold font not according to their Unicode mapping, but according to the "raw" glyph index in the Normal (ie. not bold) font file. So, e.g. if the glyph index for the letter 'N' in the non-bold, regular, font file is $0031, it will pick whatever character is under $0031 in the bold version (say M, because Bold might have an extra character before N), regardless of whether its mapping is N or something else, and incorrectly render it on the page. 

Very simple, 
1 - there is a page with two identically sentences.
2 - The first sentence bolds text "blasting" with font Arialtrans. Rendered text is "blasting"
3 - The second sentence bolds the same text "blasting" using the same font with  @font-face. Rendered text is "dlasting" instead of "blasting".

Will attach testcase.

Reproducible: Always

Comment 1

7 years ago
Created attachment 542005 [details]
font Arialtrans.ttf

Comment 2

7 years ago
Created attachment 542006 [details]
font Arialtransbd.ttf

Comment 3

7 years ago
Created attachment 542008 [details]
tescase showing bug.

When the attached font are installed, this HTML shows the two same sentences, using the same font, rendering different characters.

Comment 4

7 years ago
Created attachment 542010 [details]
A screenshot

An screenshot showing problem.


7 years ago
Version: unspecified → 5 Branch
Component: Graphics → Layout: Text
QA Contact: thebes → layout.fonts-and-text
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