Sort references by order of appearance starting midway through the document

I would like to have a document formed of two parts, with a common bibliography but where the sorting is based on the order of appearance in the second section. The natural thing to my mind would be to use defernumbers=true and have the first \printbibliography print the contents of the second section (which I make a refsegment over a refsection as I want a common bibliography).

The output I get however is

One [1][2] Two [1][3][4][2]

where I would like to have

One [1][4] Two [1][2][3][4]

with the order of refences being determined primarily by order of appearance in the second section.

\documentclass{article}

\usepackage[
backend=biber,
citestyle=numeric,
defernumbers=true,
refsegment=section,
sorting=none
]{biblatex}

\begin{document}
\section{One}
\cite{bertram}\cite{doody}

\section{Two}
\cite{bertram}\cite{glashow}\cite{gillies}\cite{doody}

\printbibliography[segment=2]

\end{document}


Is it possible to sort by first appearance after a given point, midway through the document?

The motivation is to prepare a single document with some cover note, where the first section can reference the same bibliography as the main document but can also be removed and the main document appear complete (i.e. the second section + bibliography looks identical whether compiled with the first section or not, with the order of citations in the bibliography determined by the order in which they are cited in the second section).

Just copying from the aux file what biblatex adds to stop citations in a caption counting if they are copied to the list of tables results in

\documentclass{article}

\usepackage[
backend=biber,
citestyle=numeric,
defernumbers=true,
refsegment=section,
sorting=none
]{biblatex}

\begin{document}
\section{One}
\boolfalse {citerequest}\boolfalse {citetracker}\boolfalse {pagetracker}\boolfalse {backtracker}\boolfalse{citetracker}
\cite{bertram}\cite{doody}

\section{Two}
\booltrue {citerequest}\booltrue {citetracker}\booltrue {pagetracker}\booltrue {backtracker}\booltrue{citetracker}
\cite{bertram}\cite{glashow}\cite{gillies}\cite{doody}

\printbibliography[segment=2]

\end{document}


(There is probably a more official interface but...)

• Using \boolfalse{citerequest} ... \booltrue{citerequest} seems sufficient. – Werner Sep 16 '16 at 2:23