Package pdflscape has strange indent when including an abstract?

Question

I am trying to use the pdflscape package. When I include an abstract, the indenting on the left margin becomes really large. Here is a minimal working example:

\documentclass[letterpaper, 12pt]{article}
\usepackage{pdflscape}
\begin{document}
\abstract{
    The abstract of my document.
}
\begin{landscape}
    Why is the left margin so large here?
\end{landscape}
\end{document}

If you comment out the abstract then the indenting is as expected. Any idea what is going on here? Suggested workarounds?

Answer 1

In class article, abstract is an environment, not a command. As command it executes the begin part of the environment and the abstract will end with the end of the whole document.

As environment it works as expected:

\documentclass[letterpaper, 12pt]{article}
\usepackage{pdflscape}
\begin{document}
\begin{abstract}
    The abstract of my document.
\end{abstract}
\begin{landscape}
    Why is the left margin so large here?
\end{landscape}
\end{document}