Describe undocumented third argument to touchline()
diff --git a/Doc/lib/libcurses.tex b/Doc/lib/libcurses.tex
index bf3505a..33dea5a 100644
--- a/Doc/lib/libcurses.tex
+++ b/Doc/lib/libcurses.tex
@@ -1024,9 +1024,11 @@
input at the end of that time.
\end{methoddesc}
-\begin{methoddesc}[window]{touchline}{start, count}
+\begin{methoddesc}[window]{touchline}{start, count\optional{, changed}}
Pretend \var{count} lines have been changed, starting with line
-\var{start}.
+\var{start}. If \var{changed} is supplied, it specifies
+whether the affected lines are marked as
+having been changed (\var{changed}=1) or unchanged (\var{changed}=0).
\end{methoddesc}
\begin{methoddesc}[window]{touchwin}{}