# \footnoteref (= modified \footnotemark) works perfectly fine *outside* of chapters but not within them

Because I need a reference to the same footnote, I like to use \footnoteref which is defined here.

Writing

\documentclass[12pt,a4paper]{report}
\usepackage[british]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage[bottom,hang]{footmisc}
\usepackage{hyperref}
\usepackage{zref-perpage}
\usepackage[gen]{eurosym}
\usepackage{footnote}
\makesavenoteenv{tabular}
\makesavenoteenv{equation}
\zmakeperpage{footnote}

% Remove counter "footnote" from the reset counter list
% of counter "chapter".
\usepackage{remreset}
\makeatletter
\@removefromreset{footnote}{chapter}
\makeatother
\usepackage[labelfont=bf]{caption}

\makeatletter
\newcommand\footnoteref[1]{\protected@xdef\@thefnmark{\ref{#1}}\@footnotemark}
\makeatother

\begin{document}
$$\begin{tabular}{@{} l r @{}} Wood\footnote{\label{one}Footnote for wood.}\ \ & 10,000\ \euro\\ Steel\ \ & 25,000\ \euro\\ Coal\ \ & 5,000\ \euro\\ Oil\ \ & 100,000\ \euro\\ \hline Sum\ \ & 140,000\ \euro \end{tabular}$$
$$\begin{tabular}{@{} l r @{}} Wood\footnoteref{one}\ \ & 10,000\ \euro\\ Steel\ \ & 25,000\ \euro\\ Coal\ \ & 5,000\ \euro\\ Oil\ \ & 100,000\ \euro\\ \hline Sum\ \ & 140,000\ \euro \end{tabular}$$
\end{document}


results in

which is the result I would like to have. But inserting \chapter{One} between \begin{document} and the first will result in

which I would not like to have.

Where is the error in this whole thing? I cannot find it. I suppose that the definition of \footnoteref has to be modified in order to solve the problem. Or maybe some chapter/equation numbering has to be modified.

Three issues:

Issue 1:

As you load the footmisc-package, you can use its \footref-command instead of defining your own \footnoteref-command.

But you need to adjust the \footref-command to take the hyperref-package into account correctly.

You're in luck here—a discussion about a similar problem took place recently in the German-language-newsgroup de.comp.text.tex.
Subject: "Fussnoten wiederholen". (Repeating footnotes.)

Issue 2:

The amsmath-package does within the equation-environment redefine the \label-command in a way which makes it impossible to use it within footnotes within equations also. Therefore I suggest saving the \label command under a different macro name and using that within things where amsmath applies its "nice" modifications.

Issue 3:

Your \makesavenoteenv-entries make sure that "spitting out" footnotes will be delayed to a moment in time where \label-placement will be broken due to internal macros like \@currentlabel and \@currentHref being redefined already.
Therefore you need to ensure the local restoring of these macros before processing a \label-command.

\documentclass[12pt,a4paper]{report}
\usepackage[british]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage[bottom,hang]{footmisc}
\usepackage{hyperref}
\usepackage{zref-perpage}
\usepackage[gen]{eurosym}
\usepackage{footnote}
\makesavenoteenv{tabular}
\makesavenoteenv{equation}
\zmakeperpage{footnote}

% Remove counter "footnote" from the reset counter list
% of counter "chapter".
\usepackage{remreset}
\makeatletter
\@removefromreset{footnote}{chapter}
\makeatother
\usepackage[labelfont=bf]{caption}

\makeatletter
\renewcommand\footref[1]{%
\begingroup
\unrestored@protected@xdef\@thefnmark{%
\ref*{#1}%
}%
\endgroup
\ifHy@hyperfootnotes
\expandafter\@firstoftwo
\else
\expandafter\@secondoftwo
\fi
{\hyperref[#1]{\strut\H@@footnotemark}}{\@footnotemark}%
}%
}{}%

\newcommand\savedlabel{}%
\AtBeginDocument{\let\savedlabel=\label}%
\newcommand\footnotereflabel[1]{%
\@bsphack
\begingroup
\def\@currentHref{Hfootnote.\theHfootnote}\savedlabel{#1}%
\endgroup
\@esphack
}%

\makeatother

\begin{document}
\chapter{One}
$$\begin{tabular}{@{} l r @{}} Wood\footnote{\footnotereflabel{one}Footnote for wood.}\ \ & 10,000\ \euro\\ Steel\ \ & 25,000\ \euro\\ Coal\ \ & 5,000\ \euro\\ Oil\ \ & 100,000\ \euro\\ \hline Sum\ \ & 140,000\ \euro \end{tabular}$$
$$\begin{tabular}{@{} l r @{}} Wood\footref{one}\ \ & 10,000\ \euro\\ Steel\ \ & 25,000\ \euro\\ Coal\ \ & 5,000\ \euro\\ Oil\ \ & 100,000\ \euro\\ \hline Sum\ \ & 140,000\ \euro \end{tabular}$$
\end{document}