Shift horizontal line to the left

Question

I am using a horizontal rule to to separate texts, and I would like the rule to start to the left of the current left margin. I am using the following code, but apparently it is not the correct way to do that, as I get the warning: "Overfull \hbox (2.22221pt too wide) in paragraph" What is the correct way?

thanks.

\documentclass{article}
\usepackage{xcolor}
\usepackage[english]{babel}
\usepackage{blindtext}
 \newcommand{\blockline}{\noindent\hspace{-0.05\textwidth}
    \textcolor{orange}{\rule{1.05\textwidth}{5pt}}}
\begin{document}
    \noindent\blindtext

    \blockline

    \noindent\blindtext
\end{document}

Answer 1

There's a spurious blank space at the end of the first line (which you should comment out). Also, I would use \par at the beginning of the definition so \blockline always ends a paragraph; to prevent the line to be left as a widow, I would use something like\par\nobreak at the end of the definition:

\newcommand{\blockline}{\par\noindent\hspace{-0.05\textwidth}%
    \textcolor{orange}{\rule{1.05\textwidth}{5pt}}\par\nobreak}

Answer 2

I propose another definition of \blockline that is more complicated, disallows completely a break before the rule and makes easier to control the spacing before and after it:

\newcommand{\blockline}{\par\nobreak % don't break a page here
  \moveleft0.05\textwidth\vbox{% we want the rule to protrude on the left
    \hsize=1.05\textwidth % correct the length
    \kern\the\prevdepth % don't take into account the depth of the preceding line
    \kern3pt % space before the rule
    \color{orange}\hrule height 5pt width\hsize % the rule
    \kern3pt % space after the rule
  }\nointerlineskip % no additional space after the rule
}

In this way we are sure that the baselines of the preceding and following lines are exactly 3+5+3 points apart.

Answer 3

The result here is actually not due to the \hspace being incorrect as you may have thought, but in your code that inserts a spurious space:

\documentclass{article}
\usepackage{xcolor}
\usepackage[english]{babel}
\usepackage{blindtext}
\newcommand{\blockline}{\noindent\hspace{-0.05\textwidth}% <--- note the %
  \textcolor{orange}{\rule{1.05\textwidth}{5pt}}}
\begin{document}
\noindent\blindtext

\blockline

\noindent\blindtext
\end{document}