Suppress page numbers in glossaries (the number of the page, not the references)

Question

My university came up with the brilliant idea of determining that the front matter of a thesis must not show the page's numbers. I applied the solutions of this answer: suppress page numbers in document's front matter and it worked but for the glossaries pages.

I'm using the glossaries package for displaying lists of symbols, acronyms and abbreviations. The class I'm using is a custom class based on the book class.

Edit:

MWE

\documentclass[a4paper,10pt]{book}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{hyperref}
\usepackage{etoolbox}
\usepackage[nonumberlist,symbols,acronyms,abbreviations]{glossaries-    extra}
\usepackage{blindtext}

\makeglossaries
\appto\captionsenglish{%
\renewcommand*{\acronymname}{List of Acronyms}%
}
\appto\captionsenglish{%
\renewcommand*{\glssymbolsgroupname}{List of Symbols}%
}
\appto\captionsenglish{%
\renewcommand*{\abbreviationsname}{List of Abbreviations}%
}
% abbreviations:
\newabbreviation{const}{Const.}{Constitution}
% acronyms
\newacronym{LED}{LED}{Light Emitting Diode}
% symbols
\newglossaryentry{pi}{name={\ensuremath{\pi}},sort=    {pi},type=symbols,category=symbol,description={Ratio between the circumference and the radius of a circle}}

\makeatletter
\renewcommand{\pagenumbering}[1]{\gdef\thepage{\csname     @#1\endcsname\c@page}}
\makeatother

\begin{document}

\pagestyle{empty} % No page numbers
\begingroup
\frontmatter
\patchcmd{\chapter}{plain}{empty}{}{} % Patching the command so lists have no page numbers
\pagenumbering{arabic} % For showing in the index

\listoffigures % OK, page number not shown
\listoftables % OK, page number not shown

\glsaddall
\printglossaries % Don't work, the glossaries displays the page     numbers

\tableofcontents
\endgroup

\clearpage
\pagestyle{plain} % Back to the page numbering

\mainmatter

\chapter{First chapter}

\Blindtext

\chapter{Second chapter}

\Blindtext

\end{document}

Edit: to my amusement, in the MWE it works, but in the custom class, it doesn't.

Answer 1

Each glossary uses \glossarypreamble after the heading, so you just need to redefine this to override \thispagestyle{plain} issued by \chapter:

\renewcommand{\glossarypreamble}{\thispagestyle{empty}}