olink target.db generation problem in 1.77 Webhelp output

[Denis Bradford <denis.bradford@verizon.net>]

docbook-xsl-ns-1.77.1 appears to break Webhelp olinks. My build hangs 
while processing the target database. The problem seems to be the 
doctype generation in the generated targetdb, which was not there in 1.76.1:

<!DOCTYPE div
  PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";>
<div element="set ...

My workaround for now:

1. Build using collect.xref.targets="only".

2. Halt the build, edit target.db and delete the doctype.

3. Rebuild using collect.xref.targets="no".

Thanks,
Denis