Breaklines in lstset does not work sometimes

Question

I am including some code into my tex file via \lstinputlisting[]{}. Unfortunately sometimes the breaklines=true-command does not work. Example:

In line 65 the linebreak does not work, but in line 70 it works. Why? My lstset is:

\lstset{literate=
  {á}{{\'a}}1 {é}{{\'e}}1 {í}{{\'i}}1 {ó}{{\'o}}1 {ú}{{\'u}}1
  {Á}{{\'A}}1 {É}{{\'E}}1 {Í}{{\'I}}1 {Ó}{{\'O}}1 {Ú}{{\'U}}1
  {à}{{\`a}}1 {è}{{\`e}}1 {ì}{{\`i}}1 {ò}{{\`o}}1 {ù}{{\`u}}1
  {À}{{\`A}}1 {È}{{\'E}}1 {Ì}{{\`I}}1 {Ò}{{\`O}}1 {Ù}{{\`U}}1
  {ä}{{\"a}}1 {ë}{{\"e}}1 {ï}{{\"i}}1 {ö}{{\"o}}1 {ü}{{\"u}}1
  {Ä}{{\"A}}1 {Ë}{{\"E}}1 {Ï}{{\"I}}1 {Ö}{{\"O}}1 {Ü}{{\"U}}1
  {â}{{\^a}}1 {ê}{{\^e}}1 {î}{{\^i}}1 {ô}{{\^o}}1 {û}{{\^u}}1
  {Â}{{\^A}}1 {Ê}{{\^E}}1 {Î}{{\^I}}1 {Ô}{{\^O}}1 {Û}{{\^U}}1
  {œ}{{\oe}}1 {Œ}{{\OE}}1 {æ}{{\ae}}1 {Æ}{{\AE}}1 {ß}{{\ss}}1
  {ç}{{\c c}}1 {Ç}{{\c C}}1 {ø}{{\o}}1 {å}{{\r a}}1 {Å}{{\r A}}1
  {€}{{\EUR}}1 {£}{{\pounds}}1,
  breaklines=true, postbreak=\raisebox{0ex}[0ex][0ex]{\ensuremath{\color{red}\hookrightarrow\space}},
  rulecolor=\color{black}
}

Full listing:

\documentclass[a4paper,11pt]{article}
\usepackage[english]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage{amsmath}
\usepackage{bibgerm} 
\usepackage{amssymb}
\usepackage{makeidx}
\usepackage[automark]{scrpage2}
\usepackage{listings}
\pagestyle{scrheadings}
\usepackage{graphicx}
\usepackage{wrapfig}
\usepackage{subcaption}
\usepackage{siunitx}
\usepackage{multicol}
\usepackage{xcolor}
\usepackage{yfonts}
\usepackage[bw,numbered,framed,autolinebreaks]{mcode}
%\usepackage[per-mode=fraction,output-decimal-marker={,}]{siunitx}
%\usepackage{multirow}
%\usepackage{bigstrut}
%\usepackage{rotating}

\setlength{\parindent}{0ex}
\setlength{\parskip}{1.5ex plus0.5ex minus0.2ex}
\setlength{\headheight}{26pt}
\addtolength{\topmargin}{-0.2in}
\addtolength{\headsep}{0.2in}
\addtolength{\oddsidemargin}{-0.2in}
\addtolength{\textwidth}{0.5in}

\renewcommand{\topfraction}{1.0}
\renewcommand{\bottomfraction}{1.0}
\renewcommand{\textfraction}{0.0}

\newcommand{\unit}[1]{\ensuremath{\, \mathrm{#1}}}
\newcommand{\sinc}{\mathrm{sinc}}
\newcommand{\cosc}{\mathrm{cosc}}


\begin{document}
\begin{lstlisting}
def jonswap(self, w, wp = None, alpha = 0.0081, gamma = 3.3, beta = 1.25):

            S.append(alpha*gamma*gamma/elem**5*math.exp(-beta*(wp/elem)**4)*gamma**r)
        return S 
\end{lstlisting}
\end{document}

Answer 1

The problem is that breaklines doesn't take decisions. It has two simple rules for breaking:

1. Don't break the initial indentation (i.e., leave at least something other than whitespace on the line)
2. Break only at whitespace.

Since your line doesn't contain any whitespace, there's no feasible breakpoint whence no break.