[XeTeX] Problem with Malayalam book class using xelatex

[Sasi Kumar]

Hello everyone,

I had written a book using aleph and it was compiling properly till I
changed my laptop and installed everything afresh. Then it developed
several problems, some of which I could solve with help. But there
still remained some problem and finally, I decided to use xelatex.
Thus, I modified the code to suit xelatex and compiled. It compiled
without any error and gave a pdf output. But the pdf file contained
only boxes and no text. I used my favourite Rachana font with old
style letters. I am giving the entire preamble below. Could someone
tell me what I could be doing wrong? I have Rachana installed on my
system and use it to create documents occasionally with Libre Office.
In fact, I have been usng xelatex with Rachana font for writing
articles without any problem. Thus this looks rather strange!

Thank you in advance for any help.

Regards,
Sasi

My preamble:

\documentclass[a5paper,11pt,openany]{book}
\oddsidemargin=-1in
\topmargin=-1in
\usepackage{graphicx}
\let\footruleskip\undefined
\usepackage{fancyhdr}
\usepackage{multicol}
\usepackage[paperheight=22.225cm,,paperwidth=14.2875cm,lmargin=15mm,tmargin=20mm]{geometry}
\textheight=16cm
\textwidth=11cm
\usepackage{url}
\usepackage{polyglossia}
\newfontfamily \mayalamfont[Script=Malayalam]{Rachana}
\setromanfont{DejaVu Serif}

\usepackage{makeidx}
\usepackage{caption}
\setcounter{tocdepth}{0}
\usepackage{balance}
\makeatletter
\def\thickhrule{\leavevmode \leaders \hrule height 1ex \hfill \kern \z@}
\def\position{\centering}

\renewcommand{\@makechapterhead}[1]{%
 \vspace*{10\p@}%
  {\parindent \z@ \position \reset at font
        {\centering\LARGE  \thechapter .  #1}
        \par\nobreak
        \vspace*{5\p@}%
        \interlinepenalty\@M
       \par\nobreak
       \vspace*{2\p@}%
    \vskip 5mm
  }}
\makeatother

\makeatletter

\renewcommand\chapter{%
                   \vskip 25mm
                    \@afterindentfalse
                    \secdef\@chapter\@schapter}
\makeatother

\makeatletter
\renewcommand\section{\@startsection {section}{1}{\z@}%
                                   {-3.5ex \@plus -1ex \@minus -.2ex}%
                                   {2.3ex \@plus.2ex}%
                                   {\normalfont}}
\makeatother
\setlength{\parindent}{8mm}
\newcommand{\dash}{\raisebox{2pt}{\rule{3mm}{0.5pt}}}
\newcommand{\chem}[1]{\ensuremath\mathrm{#1}}
\lefthyphenmin=3
\righthyphenmin=3
\setlength{\parskip}{0cm}

\makeindex
\pagenumbering{roman}
\def\thepage{{ \roman{page}}}

\makeatletter
\DeclareOldFontCommand{\rm}{\normalfont\rmfamily}{\mathrm}
\DeclareOldFontCommand{\sf}{\normalfont\sffamily}{\mathsf}
\DeclareOldFontCommand{\tt}{\normalfont\ttfamily}{\mathtt}
\DeclareOldFontCommand{\bf}{\normalfont\bfseries}{\mathbf}
\DeclareOldFontCommand{\it}{\normalfont\itshape}{\mathit}
\DeclareOldFontCommand{\sl}{\normalfont\slshape}{\@nomath\sl}
\DeclareOldFontCommand{\sc}{\normalfont\scshape}{\@nomath\sc}
\makeatother
%================================ BODY ===================================

\begin{document}

-- 
V. Sasi Kumar
Free Software Foundation of India
Please see: http://swatantryam.blogspot.com/