Hi,

copy&paste from PDF is broken:

  \setupbodyfont [iwona]
  \starttext
    \feature[+][just-os,smallcaps] 0123456789 abcdefghijklmnopqrstuvwxyz
  \stoptext

Result:   
Expected: 0123456789abcdefghijklmnopqrstuvwxyz

(Tried in Okular, but reported for other readers as well [1])

Thanks to Marius’ git mirror I could bisect the changes since
TL 2012. It looks like the issue has been introduced with release
"stable 2013.05.27 09:10" [2].

Best regards,
Philipp


[1] http://tex.stackexchange.com/q/126333/14066
[2] http://repo.or.cz/w/context.git/commitdiff/6b2f7c5fd7a3e465f4e2662b1e5bd2c9d5cce8f8