Latex scoped \label and \ref

thesis.tex

\documentclass[12pt,a4paper,twoside,openright]{report}

%% Scope references to the chapter level.  This works by redefining
%% the \label and \ref commands so that all references have their
%% current chapter number (\thechapter) prepended to them, both at
%% label and reference time.  This prevents the referencing of things
%% outside the chapter.
%%
%% Refer to https://en.wikibooks.org/wiki/TeX/let for details on \let
%% and \renewcommand.

\let\OriginalLabel\label
\renewcommand{\label}[1]{\OriginalLabel{\thechapter-#1}}

\let\OriginalRef\ref
\renewcommand{\ref}[1]{\OriginalRef{\thechapter-#1}}


\begin{document}

\chapter{Introduction}

The value of the variable \texttt{\textbackslash{}thechapter} is now
\thechapter (it should be the number of the chapter).  It will change
each time a new chapter starts.


\chapter{Paper X}
\section{Introduction}
\label{sec:intro}

The value of the variable \texttt{\textbackslash{}thechapter} is now
\thechapter (it should be the number of the chapter).

\section{Results}

The introduction for this chapter is Section \ref{sec:intro}).


\chapter{Paper Y}
\section{Introduction}
\label{sec:intro}

\section{Results}

The introduction for this chapter is Section \ref{sec:intro}).

\chapter{Paper Z}
\section{Introduction}
\label{sec:intro}

The value of the variable \texttt{\textbackslash{}thechapter} is now
\thechapter (it should be the number of the chapter).

\section{Results}

The introduction for this chapter is Section \ref{sec:intro}).


\end{document}