As reported by Robin Lee Powell

This is still not right, since inline quoted printables can occur anywhere in a header not just at the beginning.

Implement octet-limit for quoted printable streams (js@codeartist.org--2004-public/mel-base--dev--0.5--patch-10)
js@codeartist.org--2004-public/mel-base--dev--0.5--patch-10
Keywords: 

If reading from the embedded stream exceeds the octet-count of
the stream - end-of-file is signalled.