[XeTeX] Embed full font in PDF

[maxwell]

The new version of Adobe Acrobat (which I have the misfortune to be 
using at my office) is outputting a warning where we didn't used to get 
a warning.  Namely, it complains about one particular font in our PDFs. 
The warning is:
    Cannot extract the embedded font 'LOFCAW+DejaVuSansCondensed.
    Some characters may not display or print correctly.
In fact it displays unaccented characters correctly, but leaves a blank 
where "accented" characters should appear (à, ö etc.).

This appears to be a problem for this particular DejaVu font, but not 
e.g. for CharisSIL.  But when I run pdffonts on the output pdf, I don't 
see any relevant difference between these two fonts:

ULCJWW+CharisSIL             CID TrueType  yes yes yes    5  0
...
LOFCAW+DejaVuSansCondensed   CID TrueType  yes yes yes  809  0

(The information Acrobat gives in the "Fonts" tab of its "Document 
Properties" dialog looks similar to the above.)  I thought maybe the 
problem was with the subsetting of the font (although as you can see, 
both the working Charis font and the problematic DejuVu font have only 
embedded subsets).  IIUC, font embedding is the responsibility of 
xdvipdfmx.  So I tried forcing this program to embed all fonts would 
help, by supplying the -E flag to xdvipdfmx; but this has no effect on 
the full embedding of this font, it still embeds only a subset.  (Is 
there no way to force xdvipdfmx to embed full fonts, rather than 
subsets?)  And that may not be the problem anyway, since the CharisSIL 
font is also a subset.

I've opened these PDFs in Chrome, and they display all the DejaVu 
characters just fine.  That said, I can't definitively say that the 
problem is with Acrobat; for all I know, Chrome is silently substituting 
some similar font for the accented characters (although they look right 
when I magnify the image--in particular, the 'a' with the grave looks 
identical to the 'a' without the grave--so if it's another font, it's an 
exceedingly similar one).

Has anyone else run into this problem with the DejaVu fonts and Acrobat?

I can make a MWE if that would help; I'm just hoping someone else has 
already run into this problem and has a work-around :-).

     Mike Maxwell
     University of Washington