# Reducing line spacing in chapter headings

I changed line spacing to double using \begin{doublespace}. Now for those chapter headings which are spread over two lines, I want to reduce their line spacing. How can I do that? MWE

\documentclass[oneside,12pt,chapterprefix ]{scrbook}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{enumerate}
\usepackage{setspace,xparse}
\usepackage{caption}
\usepackage{lipsum}
\let\oldchapter\chapter
\RenewDocumentCommand{\chapter}{s o m}{%
\IfBooleanTF{#1}
{% \chapter*
\oldchapter*{\singlespacing #3}%
}{% \chapter
\IfValueTF{#2}
{% \chapter[..]{...}
\oldchapter[#2]{\singlespacing #3}%
}{% \chapter{...}
\oldchapter[#3]{\singlespacing #3}%
}%
}%
}
\title{Title of Thesis}

\date{2016}
\titlehead{A Thesis submitted for the degree of Doctor of Philosophy}
\publishers{}
\usepackage[left=1.50in,   footskip=0.4in ]{geometry}
\begin{document}
\frontmatter
\tableofcontents
%   \listoftables
%   \listoffigures
\include{Abs}
\begin{doublespace}
\mainmatter
\include{chap1}
\include{chap2}
\end{doublespace}
\backmatter
\bibliographystyle{IEEEtran}
\bibliography{myBib}
\end{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Chapter 1 File
\chapter{A default chapter title}
\label{chap1}
\lipsum[1]

%% Chapter 2 File
\chapter{A lengthy chapter title that spans multiple lines}
\label{chap2}
\lipsum[1]

• Why should one want that inconsistency?
– Jan
Jan 12 '17 at 17:00

The following example updates \chapter and prepends it with \singlespacing so the entire heading is set without the doublespacing spread:

\documentclass{report}

\usepackage{setspace,xparse,lipsum}

\let\oldchapter\chapter
\RenewDocumentCommand{\chapter}{s o m}{{%
\singlespacing
\IfBooleanTF{#1}
{% \chapter*
\oldchapter*{#3}%
}{% \chapter
\IfValueTF{#2}
{% \chapter[..]{...}
\oldchapter[#2]{#3}%
}{% \chapter{...}
\oldchapter{#3}%
}%
}%
}}

\begin{document}

\doublespacing

%\tableofcontents

\chapter{A default chapter title}
\lipsum[1]

\chapter{A lengthy chapter title that spans multiple lines}
\lipsum[1]

\end{document}

• Thanks. Your code worked. However, it does not work if chapters are sparate files as in my case. MWE is given below
– Ehsa
Jan 13 '17 at 5:46
• I have included MWE in original question. It does not work for MWE.
– Ehsa
Jan 13 '17 at 10:01
• The first paragraph is indented. Nevermind +1 :-) Mar 26 '17 at 13:11