下面的例子，尽管生成的结果HTML看起来没问题，但却显示了一条错误消息。
示例文件：
\documentclass{article}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@incollection{lin_impressions_1936,
address = {Berkeley},
title = {Impressions on {Reaching} {America}},
booktitle = {Land without {Ghosts}: {Chinese} {Impressions} of {America} from the {MidNineteenth} {Century} to the {Present}},
publisher = {University of California Press},
author = {Lin, Y. T.},
editor = {Arkush, R. D. and Lee, L. O.},
year = {1936},
pages = {160--63},
}
\end{filecontents}
\usepackage[backend=biber]{biblatex}
\addbibresource{\jobname.bib}
\begin{document}
Lorem ipsum~\cite{lin_impressions_1936}.
Dolor sit amet~\textcite{lin_impressions_1936}.
\printbibliography
\end{document}
编译自：
make4ht -x -u article
生成HTML：
错误信息：
[ERROR] htlatex: Compilation errors in the htlatex run
[ERROR] htlatex: Filename Line Message
[ERROR] htlatex: ./article.aux 10 Package etoolbox Error: Boolean '\ifrefcontextdefaults' undefined.
[ERROR] htlatex: ./article.aux 12 Package etoolbox Error: Boolean '\ifrefcontextdefaults' undefined.
文件内容.log：
! Package etoolbox Error: Boolean '\ifrefcontextdefaults' undefined.
See the etoolbox package documentation for explanation.
Type H <return> for immediate help.
...
l.12 ...pressions_1936}{nty/global//global/global}
Your command was ignored.
答案1
看起来这是一个biblatex.4ht只在 XeTeX 模式下发生的错误。罪魁祸首如下：
\ifdefined\XeTeXversion
\def\abx@aux@defaultrefcontext#1#2#3{%
\global\boolfalse{refcontextdefaults}%
\csxdef{blx@assignedrefcontextbib@#1@\detokenize{#2}}{\detokenize{#3}}}
\fi
当 XeTeX 处于活动状态时，它会重新定义一些内部宏，添加额外的宏\detokenize来保护特殊字符。似乎refcontextdefaultsBibLaTeX 不再使用布尔变量，所以我们可以删除此行。这似乎可以解决问题。
以下是完整biblatex.4ht修复程序：
% biblatex.4ht (2021-12-27-13:23), generated from tex4ht-4ht.tex
% Copyright 2007-2009 Eitan M. Gurari
% Copyright 2009-2021 TeX Users Group
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either
% version 1.3c of this license or (at your option) any
% later version. The latest version of this license is in
% http://www.latex-project.org/lppl.txt
% and version 1.3c or later is part of all distributions
% of LaTeX version 2005/12/01 or later.
%
% This work has the LPPL maintenance status "maintained".
%
% The Current Maintainer of this work
% is the TeX4ht Project <http://tug.org/tex4ht>.
%
% If you modify this program, changing the
% version identification would be appreciated.
\immediate\write-1{version 2021-12-27-13:23}
\def\make:blx:ver#1.#2#3\relax{%
%\ifdim#1pt< 3pt \xdef\blx:ver:no{2}\else\xdef\blx:ver:no{3}\fi%
\gdef\blx:ver:no{#1}
\gdef\blx:subver:no{#2}
}
\expandafter\make:blx:ver\[email protected]\relax
\ifx\a:printshorthands\Undef\let\blx@shorthands\@empty\fi
\ifx\blx@startbib\:UnDef
\pend:def\blx@shorthands{%
\pend:def\blx@bibinit{%
\HAssign\shorthands:cnt=0
\NewConfigure{printfield-shorthand}{2}%
\Configure{printfield-shorthand}%
{\gHAdvance\shorthands:cnt by 1\relax
\ifnum \shorthands:cnt=1 \a:printshorthands
\else \c:printshorthands \fi
}
{\d:printshorthands}%
\append:def\endtheshorthands{\b:printshorthands}%
\csname a:@shorthands\endcsname}
}
\ifx\b:printshorthands\Undef\let\endtheshorthands\@empty\fi
\def\a:entryhead{CVR}
\def\a:entryhead:full{CV Radhakrishnan}
\ifx\bib@macro@entryhead:name\UnDef
\let\bib@macro@entryhead:name\@empty\fi
\ifx\bib@macro@entryhead:full\UnDef
\let\bib@macro@entryhead:full\@empty\fi
\gdef\BibFileName[#1]#2{\expandafter\xdef\csname
BibFileName#1\endcsname{#2}}
\newcount\sv:sec:cnt
\def\bibSecConfigure{%
\let\save:section\section
\global\sv:sec:cnt=\c@secnumdepth
\def\section{\@ifstar
{\c@secnumdepth=0\relax\save:section}%
{\c@secnumdepth=\sv:sec:cnt\save:section}}%
}
\gHAssign\bibN=0
\ifdefined\TE@hook\else%
\def\TE@hook{}%
\fi%
\AtBeginDocument{%
\Configure{ifthenelse}{\TE@hook}
}
\:CheckOption{ooffice}\if:Option
\def\bibConfigure{\ConfigureList{thebibliography}%
{\IgnorePar\EndP \gHAdvance\bib:N by 1
\HCode{<text:bibliography text:name="bib-\bib:N" >
<text:bibliography-source>\Hnewline
<text:index-title-template>}
\NoFonts\ref:name\EndNoFonts
\HCode{</text:index-title-template>\Hnewline
%
<text:bibliography-entry-template\Hnewline
text:bibliography-type="custom1"
text:style-name="Bibliography11">\Hnewline
%
<text:index-entry-bibliography
text:bibliography-data-field="identifier"/>\Hnewline
%
<text:index-entry-span>: </text:index-entry-span>\Hnewline
<text:index-entry-bibliography
text:bibliography-data-field="author" />\Hnewline
<text:index-entry-span>, </text:index-entry-span>\Hnewline
%
<text:index-entry-bibliography
text:bibliography-data-field="title" />\Hnewline
<text:index-entry-span>, </text:index-entry-span>\Hnewline
%
<text:index-entry-bibliography
text:bibliography-data-field="year" />\Hnewline
</text:bibliography-entry-template>\Hnewline\Hnewline
</text:bibliography-source>\Hnewline
<text:index-body>\Hnewline}%
\let\en:bib=\empty
}%
{\en:bib\HCode{</text:index-body></text:bibliography>}}
{\en:bib\gdef\en:bib{\HCode{</text:p>\Hnewline}}%
\HCode{<text:p text:style-name="p-bibitem">}%
\gHAdvance\bibN by 1
\HCode{<text:reference-mark
text:name="X0-\csname BIB-\bibN\endcsname">%
</text:reference-mark>}%
}%
{}{}
}
\else
\def\bibConfigure{%
\ConfigureList{thebibliography}
{\ifvmode \IgnorePar \fi \EndP \EndP
\HCode {<dl class="thebibliography">}%
%
% This is for linking citations with biblist items which
% are in a different file when output is split into different
% chunks. [CVR 2012-09-27]
%
%
% <biblatex-2.2>
%
\immediate\write\@auxout{%
\string\BibFileName[\therefsection]{\FileName}}%
%
% </biblatex-2.2>
%
\PushMacro \end:itm \global \let \end:itm =\empty}%
{\ifvmode \IgnorePar \fi \EndP
\PopMacro \end:itm \global \let \end:itm \end:itm \EndP
\HCode {</dd></dl>}\ShowPar}%
{\ifvmode \IgnorePar \fi \EndP \gHAdvance \bibN by 1
\end:itm \global \def \end:itm {\EndP \Tg </dd>}%
\HCode {<dt id="X\therefsection-\abx@field@entrykey"
class="thebibliography">}\bgroup \bf}%
{\ifvmode \IgnorePar \fi \EndP
\egroup
\HCode {</dt><dd\Hnewline id="bib-\bibN"
class="thebibliography">}%
\par \ShowPar}%
}
\fi
\NewConfigure{printshorthands}{4}
\NewConfigure{@shorthands}[1]{\concat:config\a:@shorthands{#1}}
\let\a:@shorthands\empty
% \def\nolinkurl{\o:url:}
% \def\blx@checksum{\ifx \blx@checksum@old \blx@checksum@new \else
% \blx@warning@noline {Page references have changed.\MessageBreak
% Rerun to get references right}\@tempswatrue \blx@reruntrue \fi
% \@nameuse {blx@rerun}}
\def\blx@checksum#1#2#3{%
\begingroup
\blx@tempcnta\the\numexpr0#2*0#3\relax
\blx@tempcntb\blx@tempcnta
\divide\blx@tempcntb10
\multiply\blx@tempcntb10
\advance\blx@tempcnta-\blx@tempcntb
\xdef#1{#1\the\blx@tempcnta}%
\endgroup}
\@ifpackagelater{biblatex}{2018/03/01}{\let\blx:pend:def\pend:defI}{\let\blx:pend:def\pend:def}
\blx:pend:def\blx@bibliography{\bibSecConfigure%
\pend:def\blx@bibinit{%
\bibConfigure
\csname onthebibliography:list\endcsname
}%
}
\let\en:bib\@empty
\newcounter{bib}
\ifnum\blx:ver:no < 3
\protected\def\blx@bbl@entry#1#2#3{%
\begingroup
\def\texht@bibkey{#1}
\edef\abx@field@entrykey{\detokenize{#1}}%
\global\advance\c@bib 1
\immediate\write\@auxout{\string\expandafter\string\gdef
\string\csname\space BIB-\thebib\string\endcsname
{\expandafter\strip@prefix\meaning\texht@bibkey}}%
\Tag{)QX\therefsection-#1}{\thebib}%
\blx@setoptions@type{#2}%
\blx@bbl@options{#3}%
\blx@setoptions@entry
\edef\blx@bbl@data{blx@data@\the\c@refsection @\abx@field@entrykey}%
\csuse\blx@bbl@data
\cslet\blx@bbl@data\@empty
\blx@bbl@addfield{entrykey}{\abx@field@entrykey}%
\blx@bbl@addfield{entrytype}{#2}%
\blx@imc@iffieldundef{options}
{}
{\blx@bbl@fieldedef{options}{\expandonce\abx@field@options}}}
%
\protected\def\blx@finentry{%
\unspace
\a:finentry
\finentrypunct
\blx@postpunct
\b:finentry
\blx@initunit
}
%
\else
% Biblatex 3.0
%
% Hacks for biblatex
% MakeUppercase is redefined by tex4ht, biblatex tries to redefine it as well, but it relies on original
% LaTeX version:
\DeclareRobustCommand{\MakeUppercase}[1]{{%
\def\i{I}\def\j{J}%
\def\reserved@a##1##2{\let##1##2\reserved@a}%
\expandafter\reserved@a\@uclclist\reserved@b{\reserved@b\@gobble}%
\let\UTF@two@octets@noexpand\@empty
\let\UTF@three@octets@noexpand\@empty
\let\UTF@four@octets@noexpand\@empty
\blx@hook@uc\protected@edef\reserved@a{\uppercase{#1}}%
\reserved@a
}}
% Same applies also for \MakeLowercase
\DeclareRobustCommand{\MakeLowercase}[1]{{%
\def\reserved@a##1##2{\let##2##1\reserved@a}%
\expandafter\reserved@a\@uclclist\reserved@b{\reserved@b\@gobble}%
\let\UTF@two@octets@noexpand\@empty
\let\UTF@three@octets@noexpand\@empty
\let\UTF@four@octets@noexpand\@empty
\blx@hook@lc\protected@edef\reserved@a{\lowercase{#1}}%
\reserved@a
}}
% I don't really understand this, but language processing is broken by default
% with biblatex. It loads language file, but it executes code which should be
% executed only in the case if the language file fails, it displays an error message
% and language handling doesn't work. When we execute following code, the language
% files are loaded before checking of the success and it seems to work.
\AtBeginDocument{%
\@ifpackageloaded{babel}
{% This is required for languages which are never explicitly selected
% It seems this code was executed also with Polyglossia, where it caused compilation error
\@ifpackageloaded{polyglossia}{}{%
\def\do#1{\blx@lbxinput{#1}{}{}}%
\ifx\@empty\bbl@loaded\else%
\expandafter\docsvlist\expandafter{\bbl@loaded}%
\fi}}{}%
}
\fi % end of version boolean
\NewConfigure{finentry}{2}
\def\:tempc[#1]#2{%
\expandafter\ifx \csname a:printfield-#2\endcsname\relax
\NewConfigure{printfield-#2}{2}%
\a:printfield{printfield-#2}%
\fi
\Configure{blx@unit}%
{\csname a:printfield-#2\endcsname}%
{\csname b:printfield-#2\endcsname}%
\csname o:\string\blx@printfield:\endcsname[#1]{#2}%
}
\expandafter\HLet\csname\string\blx@printfield\endcsname\:tempc
\NewConfigure{printfield}[1]{\def\a:printfield##1{#1}}
\Configure{printfield}{%
\Configure{#1}%
{\HCode{<!--#1-->}}%
{\HCode{<!--/#1-->}}%
}
\def\:tempc[#1]#2{%
\expandafter\ifx \csname a:bibstring-#2\endcsname\relax
\NewConfigure{bibstring-#2}{2}%
\a:printfield{bibstring-#2}%
\fi
\Configure{blx@unit}%
{\csname a:bibstring-#2\endcsname}%
{\csname b:bibstring-#2\endcsname}%
\csname o:\string\blx@bibstring:\endcsname[#1]{#2}%
}
\expandafter\HLet\csname\string\blx@bibstring\endcsname\:tempc
\def\:tempc[#1]#2{%
\expandafter\ifx \csname a:bibcpstring-#2\endcsname\relax
\NewConfigure{bibcpstring-#2}{2}%
\a:printfield{bibcpstring-#2}%
\fi
\Configure{blx@unit}%
{\csname a:bibcpstring-#2\endcsname}%
{\csname b:bibcpstring-#2\endcsname}%
\csname o:\string\blx@bibcpstring:\endcsname[#1]{#2}%
}
\expandafter\HLet\csname\string\blx@bibcpstring\endcsname\:tempc
\def\:tempc[#1]#2{%
\expandafter\ifx \csname a:biblcstring-#2\endcsname\relax
\NewConfigure{biblcstring-#2}{2}%
\a:printfield{biblcstring-#2}%
\fi
\Configure{blx@unit}%
{\csname a:biblcstring-#2\endcsname}%
{\csname b:biblcstring-#2\endcsname}%
\csname o:\string\blx@biblcstring:\endcsname[#1]{#2}%
}
\expandafter\HLet\csname\string\blx@biblcstring\endcsname\:tempc
\def\:tempc[#1]#2{%
\expandafter\ifx \csname a:bibucstring-#2\endcsname\relax
\NewConfigure{bibucstring-#2}{2}%
\a:printfield{bibucstring-#2}%
\fi
\Configure{blx@unit}%
{\csname a:bibucstring-#2\endcsname}%
{\csname b:bibucstring-#2\endcsname}%
\csname o:\string\blx@bibucstring:\endcsname[#1]{#2}%
}
\expandafter\HLet\csname\string\blx@bibucstring\endcsname\:tempc
\NewConfigure{biblatex-style}[2]{%
\def\:temp{#1}%
\ifx \:temp\blx@cbxfile
#2%
\global\let\biblatex:style\def
\fi
}
\def\biblatex:style{}
\Configure{biblatex-style}{}{}
\pend:def\at:docend{%
\ifx \UnDef\biblatex:style
\:warning{\string\Configure{biblatex-style}{\blx@cbxfile}{...}
not available}%
\fi
}
\let\blx:item\@item
\def\@item[#1]{%
\blx:item[#1]%
\ifhmode \spacefactor\blx@sf@par\fi
}
\let\blx@resetpuncthook\@empty
\let\blx@csq@ifkernmark\@empty
\newskip\blx@unitmark
\blx@unitmark=10pt plus 1pt minus 1pt
\let\abx@aux@page\@gobbletwo
\let\abx@aux@fnpage\@gobbletwo
\let\abx@aux@refsection\@gobbletwo
%
% <[email protected]> reported that After updating
% biblatex and biblatex.ht to versions 2.2 respectively
% 2012-09-28-17:49 (using MiKTeX 2.9 64 bit), tex4ht seemed no longer
% respected the defernumbers option in biblatex.sty: When applied to
% the attached file tex4hterror.tex.
%
% The problem was due to nullifying \abx@aux@number which in fact
% should have been redefined to \blx@aux@number when defernumbers
% option is true.
%
% This is done now and as per Kristian, the fix works fine now.
%
\ifnum\blx:ver:no < 3
%
\protected\def\blx@aux@number#1#2#3#4{%
\blx@bbl@addentryfield{\detokenize{#2}}{#3}{localnumber}{#4}%
\ifblank{#4}%
{}%
{\csgdef{blx@labelnumber@#3}{#4}%
%\blx@addchecksum{#1}{#4} % this can cause a nodocument error!
}}
%
\iftoggle{blx@defernumbers}%
{\setkeys{blx@opt@pre}{labelnumber}%
\let\blx@thelabelnumber\blx@addlabelnumber
\let\abx@aux@number\blx@aux@number}%
{\let\blx@thelabelnumber\relax
\let\abx@aux@number\@gobblefour}
%
\else
\def\@gobblefive#1#2#3#4#5{}%
\protected\def\blx@aux@number#1#2#3#4#5{%
\blx@bbl@addentryfield{\detokenize{#2}}{#3}{localnumber}{#4}{#5}%
\blx@bbl@addentryfield{\detokenize{#2}}{#3}{labelnumber}{#4}{#5}%
\global\toggletrue{blx@localnumber}%
\ifblank{#5}
{}
{\csgdef{blx@labelnumber@#3@#4}{#5}}}
\iftoggle{blx@defernumbers}%
{\setkeys{blx@opt@pre}{labelnumber}%
\let\blx@thelabelnumber\blx@addlabelnumber
\let\abx@aux@number\blx@aux@number}%
{\let\blx@thelabelnumber\relax
\let\abx@aux@number\@gobblefive}
\fi % end of version boolean
%
\AtEndDocument{%
\def\abx@aux@page#1#2{\blx@addpagesum{#1}{#2}}%
\def\abx@aux@fnpage#1#2{\blx@addpagesum{#1}{#2}}%
}
%
\def\blx@begunit{%
\toggletrue{blx@tempa}%
\iftoggle{blx@insert}%
{\iftoggle{blx@unit}%
{\begingroup
\let\blx@begunit\@empty
\let\blx@endunit\@empty
\let\blx@endnounit\@empty
\blx@unitpunct\blx@postpunct
\endgroup
\global\togglefalse{blx@unit}%
\togglefalse{blx@tempa}}
{\blx@postpunct}%
\iftoggle{blx@block}%
{\begingroup
\let\blx@begunit\@empty
\let\blx@endunit\@empty
\let\blx@endnounit\@empty
\newblockpunct
\endgroup
\global\togglefalse{blx@block}%
\togglefalse{blx@tempa}}%
{}}%
{}%
\blx@postpunct
\blx@imc@resetpunctfont
\iftoggle{blx@tempa}%
{}%
{\global\togglefalse{blx@insert}}%
\csname a:blx@unit\endcsname
\blx@leavevmode
\begingroup
\Configure{blx@unit}{}{}%
}
\def\blx@endunit{%
\endgroup
\csname b:blx@unit\endcsname%
\Configure{blx@unit}{}{}%
\global\toggletrue{blx@insert}%
\global\toggletrue{blx@lastins}%
}
\NewConfigure{blx@unit}{2}
%
\else
\fi
\ifdefined\XeTeXversion
\def\abx@aux@defaultrefcontext#1#2#3{%
\csxdef{blx@assignedrefcontextbib@#1@\detokenize{#2}}{\detokenize{#3}}}
\fi
\renewrobustcmd*{\addnbspace}{%
\unspace\blx@postpunct%
% insert real non-breaking space character
\nobreakspace\blx@imc@resetpunctfont}
\NewConfigure{thebibliography}{4}
\append:def\blx@bibinit{\a:bibinit}%
\NewConfigure{bibinit}{1}%
\let\blx@anchors\@empty
\let\bib@field@entrykey\@empty
\protected\def\blx@anchor{%
\xifinlist{X\the\c@refsection -%@
\bib@field@entrykey}{\blx@anchors}%
{}%
{\listxadd\blx@anchors{X\the\c@refsection -%@
\bib@field@entrykey}%
\hyper:natanchorstart{X\the\c@refsection -%@
\bib@field@entrykey}%
\hyper:natanchorend}}
\protected\def\blx@bibhyperref{%
\@ifnextchar[%]
{\blx@bibhyperref@i}%
{\blx@bibhyperref@i[\bib@field@entrykey]}}%
\long\def\blx@bibhyperref@i[#1]#2{%
\hyper:natlinkstart{X\the\c@refsection -%@
#1}%
#2\hyper:natlinkend}%
\protected\long\def\blx@bibhyperlink#1#2{%
\hyper:natlinkstart{X\the\c@refsection -%:
#1}%
#2\hyper:natlinkend}%
\protected\long\def\blx@bibhypertarget#1#2{%
\@bsphack
\hyper:natanchorstart{X\the\c@refsection -%:
#1}%
\@esphack
#2\hyper:natanchorend}%
\let\blx@ifhyperref\@firstoftwo
% Oleg Domanov [email protected] reports:
% tex4ht ends with an error when compiles biblatex files. I'm on
% Windows, texlive 2012. I put here a minimal example and files
% generated with the command latexmk test && mk4ht oolatex test
%
% https://www.dropbox.com/s/hn1zm40htqs13mf/t4htlink.zip
%
% There is a superfluous \relax in the file test.tmp, line 65 which
% seems to cause the error.
%
% Changes to cope with biblatex upgrade caused this problem. It is now
% fixed. --CVR 2012/10/26
%
\:CheckOption{ooffice}\if:Option
\def\hyper:natanchorstart#1{\Link{}{#1}\EndLink}%
\def\hyper:natlinkstart#1{\Link{#1}{}}%
\else
\def\hyper:natanchorstart#1{%
\expandafter\ifx\csname QXpage.\thepage\endcsname\relax%
\Tag{)Qpage.\thepage}{\file:id}%
\HCode{<a id="page.\thepage"></a>}%
\expandafter\xdef\csname QXpage.\thepage\endcsname{0}%
\fi
\Link[\csname BibFileName\therefsection\endcsname]{}{#1}\EndLink}
\def\hyper:natlinkstart#1{%
\expandafter\ifx\csname QXpage.\thepage\endcsname\relax%
\Tag{)Qpage.\thepage}{\file:id}%
\HCode{<a id="page.\thepage"></a>}%
\expandafter\xdef\csname QXpage.\thepage\endcsname{0}%
\fi
\Link[\csname BibFileName\therefsection\endcsname]{#1}{}}
\fi
\def\hyper:natanchorend{}
\def\hyper:natlinkend{\EndLink}
\def\writeCiteLink#1{\immediate\write\@mainaux{%
\string\@namedef{#1.\thepage}{\FileName}}}
\let\blx@addpagesum\@gobbletwo
% \let\nolinkurl\relax
\ifx\blx:ver:no < 3
%
% biblatex 2.9a
%
% Newly added to process {keylist} environment (CVR)
%
\let\keylist\description
\let\endkeylist\enddescription
\def\keyitem#1{\item[#1]}%
%
%
\else
%
% biblatex 3.0
%
\let\keylist\Un:def
\let\endkeylist\Un:def
\newenvironment*{keylist}
{\list{}{%
\setlength{\labelwidth}{1.25in}%
\setlength{\labelsep}{10pt}%
\setlength{\leftmargin}{0pt}%
\setlength{\itemsep}{0pt}%
\raggedright%
\renewcommand*{\makelabel}[1]{\hss\bfseries##1}}}
{\endlist}
%
\def\keyitem#1{%
\item[#1]
\begingroup
\keyitemhook%
\blx@bibinit%
\midsentence\ifbibstring{#1}{}{\latintext}\biblstring{#1}%
\expandafter\lbx@initnamehook\lsmartoftext%
\par\nobreak
\midsentence\ifbibstring{#1}{}{\latintext}\bibsstring{#1}%
\expandafter\lbx@initnamehook\ssmartoftext%
\endgroup
\par\nobreak}
\fi % End of version boolean
\ConfigureList{keylist}%
{\EndP\HCode{<dl \a:LRdir class="description">}%
\PushMacro\end:itm
\global\let\end:itm=\empty}%
{\PopMacro\end:itm \global\let\end:itm \end:itm
\EndP\HCode{</dd></dl>}\ShowPar}%
{\end:itm \global\def\end:itm{\EndP\Tg</dd>}\HCode{<dt
class="description">}\bgroup \bf}%
{\egroup\EndP\HCode{</dt><dd\Hnewline class="description">}}
\let\:temp\do
\def\do#1{%
\patchcmd#1%
{\color@begingroup}%
{\color@begingroup\toggletrue{blx@footnote}}%
{\togglefalse{blx@tempa}\listbreak}%
{}}%
\docsvlist{%
\@footnotetext,% latex
\H@@footnotetext,% hyperref
\scr@saved@footnotetext,% koma-script 3.x
\l@dold@footnotetext,% ledmac
\l@doldold@footnotetext,% ledmac
\@fntORI}% frenchle
\let\do\:temp
\pend:defI\blx@backref{%
% prevent duplicate backlink on the same page
\ifcsdef{bk##1\thepage}{}{%
% insert link to the page
\html:addr\Link-{}{x\last:haddr}\EndLink%
% save link to the .xref file
\Tag{)Q##1\thepage}{x\last:haddr}%
% we need to save the link destination in .xref file
% too, otherwise \Link command would issue warning
\Tag{)Qx\last:haddr}{\FileNumber}%
}%
% declare this backlink destination as used, so we don't
% declare another one with the same name
\expandafter\gdef\csname bk##1\thepage\endcsname{}%
}
% version of \hyperlink that links back to saved link in citation
% on the given DVI page
\def\bbx:hyperlink#1#2{
% first argument is destination used by Hyperref, second is page number
% test if we saved link to the current bibitem and page
\ifTag{)Q\abx@field@entrykey#2}{%
\Link{\LikeRef{)Q\abx@field@entrykey#2}}{}#2\EndLink%
}%
{#2}% print just page number if there is no saved link
}
% we need to redefine pageref format, which is used for printing of
% back link page numbers. custom \hyperlink command is used
\DeclareListFormat{pageref}{%
% we redefine \hyperlink command to link page numbers in backreferences
% back to the citations on the given pages
\let\orig:hyperlink\hyperlink%
\let\hyperlink\bbx:hyperlink%
\ifnumless{\abx@pagerefstyle}{0}
{\usebibmacro{list:plain}%
\ifhyperref
{\hyperlink{page.#1}{#1}}
{#1}}
{\ifnumequal{\value{listcount}}{1}
{\usebibmacro{pageref:init}}
{}%
\usebibmacro{pageref:comp}{#1}%
\ifnumequal{\value{listcount}}{\value{liststop}}
{\usebibmacro{pageref:dump}}
{}}
\let\hyperlink\orig:hyperlink%
}
\Hinput{biblatex}
\endinput