LaTeX changebars with pdflscape

Question

I have a very long document with a large number of tables in the appendices. These tables were a tad wide, so I change the page layout to landscape using the landscape command. To make it readable by humans, I include the pdflscape package which kindly rotates the pages when viewed on a computer screen.

Now, I'm trying to do change-bars using latexdiff and it seems to not care much for landscape pages. The bar doesn't actually seem to line up with anything (in fact, it seems to not even be visible if there are lengthy footers). I'm wondering if there is a clever solution to this problem - perhaps adjusting margins?

I tried looking through the documentation for pdflscape and nothing is sticking out to me for this one.

MWE:

\documentclass[11pt]{article}
\usepackage[letterpaper,portrait,left=1in,right=1.5in,top=1.5in,bottom=1in,headheight=1in,headsep=.5in]{geometry}
\usepackage[pdftex,traceon,rightbars]{changebar}
\usepackage{pdflscape}

\begin{document}
\cbstart{I have correct changebar.}\cbend
\begin{landscape}
\cbstart{I do not have correct changebars}\cbend
\end{landscape}
\end{document}

Answer 1

Here is a solution.

Edit here is with the original settings

\documentclass[11pt]{article}
\usepackage[pdftex,traceon,rightbars]{changebar}
\usepackage{pdflscape}

\usepackage{blindtext} 

\begin{document} 
\cbstart{I have correct changebars}\cbend

\begin{landscape}
\addtolength{\changebarsep}{\hsize}
\makeatletter\cb@positions\makeatother

\cbstart{I have correct changebars}\cbend 
\blindtext

\end{landscape}
\makeatletter\cb@positions\makeatother

\cbstart{I have correct changebars}\cbend 
\blindtext 
\end{document}

and this with typearea package

\documentclass[11pt]{article}
\usepackage{typearea}
\usepackage[pdftex,traceon,rightbars]{changebar}

\makeatletter
\newenvironment{landscape}{%
\KOMAoptions{paper=landscape,DIV=last}
\cb@positions}{%
\KOMAoptions{paper=portrait,DIV=last}
\cb@positions}
\makeatother 

\usepackage{blindtext} 

\begin{document} 
\cbstart{I have correct changebars}\cbend
\blindtext 

\begin{landscape}
\cbstart{I have correct changebars}\cbend 
\blindtext
\end{landscape}

\cbstart{I have correct changebars}\cbend 
\blindtext 
\end{document}