Problem with eulervm integral sign

Question

I'm having a problem with eulervm integral sign. I get the usual slanted instead of the expected upright integral sign. I'm using MikTeX 2.9 in combination with Lyx 2.1.3. This is the code exported by LyX. The result is the same in TeXstudio.

 %% LyX 2.1.3 created this file.  For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[12pt]{book}
\usepackage{amsmath}
\usepackage{fontspec}
\setmainfont[Mapping=tex-text]{Footlight MT Light}
\usepackage[b4paper]{geometry}
\geometry{verbose,tmargin=3cm,bmargin=3cm,lmargin=3cm,rmargin=5cm}
\usepackage{fancyhdr}
\pagestyle{fancy}
\setlength{\parskip}{\bigskipamount}
\setlength{\parindent}{0pt}
\usepackage{color}
\usepackage{float}
\usepackage{booktabs}
\usepackage{units}
\usepackage{graphicx}
\usepackage{esint}
\usepackage[unicode=true,pdfusetitle,
 bookmarks=false,
 breaklinks=false,pdfborder={0 0 1},backref=false,colorlinks=true]
 {hyperref}
\hypersetup{
 linkcolor=RoyalBlue}

\makeatletter

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% LyX specific LaTeX commands.
%% Because html converters don't know tabularnewline
\providecommand{\tabularnewline}{\\}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
%Footlight MT LIght, Heuristica
%\usepackage[garamond]{mathdesign}
\usepackage{eulervm}
\usepackage[usenames,dvipsnames]{xcolor}

%\newfontfamily\cyrillicfont{Minion Cyr Regular}
%\newfontfamily\cyrillicfont{Times New Roman}
\newfontfamily\cyrillicfont[Ligatures = TeX]{EB Garamond}





%\renewcommand*{\partpagestyle}{empty}


\fancyhead[RE,LO]{\leftmark}
\fancyhead[LE,RO]{\thepage}
\fancyfoot[C]{}

%Options: Sonny, Lenny, Glenn, Conny, Rejne, Bjarne, Bjornstrup
%\usepackage[Conny]{fncychap}

\usepackage{titlesec}
\renewcommand{\thechapter}{\Roman{chapter}}
\titleformat{\chapter}[display]
{\bfseries\Large}
{\filright\MakeUppercase{\chaptertitlename} \Huge\thechapter}
{4ex}
{\titlerule
\vspace{2ex}%
\filleft}
[\vspace{2ex}%
\titlerule]


%\DeclareMathSizes{10}{10.5}{7}{7}

\usepackage[labelfont={color=RoyalBlue,bf}]{caption}

\makeatother

\usepackage{xunicode}
\usepackage{polyglossia}
\setdefaultlanguage{serbian}


\begin{document}

\[
P\left(x_{1},x_{2}\right)=\intop_{x_{1}}^{x_{2}}p(x)dx
\]


\end{document}

Answer 1

The package esint provides some types of integrals that are not in the default font. Of course it uses its own shapes, so if you want the Euler ones, you need to disable the loading of esint.

In a normal LaTeX document, just remove \usepackage{esint} (or comment it out). In LyX (which I don't use or recommend), go to Document > Settings > Math Options and set esint to "Do not load".