Bug in Rd2dvi.sh (or doc error)? (PR#3422)

In 1.7.1 and today's r-patched in Windows, starting a continuation
line with a tab in a DESCRIPTION file causes the continuation to be
lost.  For example, I have this file:

Package: orientlib
Title: Support for orientation data
Version: 0.2
Author: Duncan Murdoch
Description: Representations, conversions and display of orientation
SO(3) data.
 See the orientlib help topic for details.
Maintainer: Duncan Murdoch <dmurdoch@pair.com>
License: GPL

The Description line is supposed to show up on 2 lines; line wrapping
might have messed it up.  When I put a tab at the start of the line
ahead of "See the orientlib help topic", I don't get that line in the
.pdf manual produced by

Rcmd Rd2dvi.sh --pdf orientlib

When I put a space there (as above), it works fine.

Could someone let me know if this is Windows-specific?  If not,
opinions about whether the error in is the script or the documentation
(Writing R Extensions, Creating R packages, Package Structure, The
DESCRIPTION file) would be welcome.

Duncan Murdoch