Dot accents have uneven height with different characters. See attachments. This is similar to bug 240525 which was fixed for Liberation fonts. DejaVu inherited this mis-feature-bug from Vera. I hope it will get fixed. DejaVu team is aware of the issue, but is not making a "decision" on it for whatever reason.
Created attachment 299825 [details] Watch the dots
Hi, please use some photo editing softrware such as GIMP / Photoshop / etc to confirm if the dots are really have uneven heights. You'll see there are uneven heights on fixed liberation-fonts because of 'illusion' effects of human eyes (proved by dragging horizontal guide lines with those softwares). I need to see there are any resources for me to look into this bug. Fixing this bug should be much easier then liberation-fonts as changes of l-f has been relied on its manufacturer.
We need to decide what to do about it. Diaeresis is usually at a different height wompared to the single dot above btw, and the latter is usually bigger as well. So actually the only thing which is incorrect in the screenshot is that the single dot above has different sizes and height. It just happened because of different people making different glyphs, who had different ideas about it. It will get fixed, but needs time to do that properly, because you can see that all fonts are affected.
Created attachment 299892 [details] U+0178 and U+03AB
Of course I used GIMP to prepare the first attachment with a few more to follow. I would strongly disagree that "diaeresis is usually at a different height..." It is more usual for fonts to be consistent with respect to this minute details. This is what makes a font rather than a collection of symbols. I am surprised that DejaVu does not have an explicit and written out standard that regulates these minute details. This is probably the reason why it is so easy to find examples illustrated in images attached bellow.
Created attachment 299893 [details] Would you rather fix this or work on obsolete glyphs?
(In reply to comment #5) > I am surprised that DejaVu does not have an explicit and written out standard > that regulates these minute details. I suppose this is the kind of contribution the project would welcome. > This is probably the reason why it is so > easy to find examples illustrated in images attached bellow. Most font projects are one-man/one-organisation creations. So they don't need any written standard, the designer mostly agrees with himself. DejaVu is a rather unusual example of large community-created font and the associated gouvernance is invented as needs are identified. Also as any FLOSS project progress is incremental and little problems are fixed when reported. While we are lucky to have one of the main designers replying in this ticket, this is really something better discussed on the DejaVu mailing list (that various experts follow).
The different position of the diaresis compared to single dot above is what we've inherited from Bitstream Vera, I guess we can trust that Bitstream had some explicit and written out rules. The letters with dot above accents were later added in DejaVu, and basically I've seen a lot of (professional) fonts behave quite differently with these dots (whatever you may say about what's usually done, test some fonts out first...), so I can quite easily understand that different developers in our project thought different things here. Basically, we don't have a mismatch either in DejaVu, we behave exactly the same as fonts like Tahoma, Arial, Minion or Myriad. Anyway, what should happen is that the precomposed glyphs should display exactly the same as composed glyphs in the end, we're working to get that right, but it's a lot of work to do these things, as there are just thousands of these glyphs to check and fix.
You are welcome to try to start this discussion on the DejaVu mailing list. I tried to do it before about half a year ago and last month but was largely ignored. The developers were aware of these glitches since day one (as they are inherited from Vera) but prefer not to make a decision. They are very territorial (working on one particular Unicode page) and they don't care about glitches across the board. To fix this will require some agreement between them, which is apparently the bigest obstacle.
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Anyway, this needs to be discussed upstream and Fedora won't fork DejaVu on its own.