"Thanks" note (footnote) placed below right column even though there is enough space on the left

Question

In this two-column document, the "thanks" note is placed below the right column even though there is enough space below the left column, and a lot of space is inserted around the heading of the first section.

If some of the text of the first section is removed, the note fits on the left, as expected. However, if text is added (!) to the first section, the note is also placed on the left (see the comments in the document).

The same thing is true for changing the "thanks" note itself - both making it shorter and making it longer will move it to the left column. The floating figure seems to be a relevant factor - I haven't been able to reproduce the problem without a figure (or a table).

I tried the bigfoot package which in fact moves the footnote to the left column, but also inserts some space before the abstract and additionally leaves just the heading (without any of the text) of the second section in the left column, directly above the footnotes. Additional space is indesirable because the conference paper length is limited, and the heading without text seems like exceptionally bad layout to me.

In another question, \makeatletter \@doclearpage \makeatother is suggested for footnotes. I have been able to reproduce the same problem with a footnote instead of a "thanks" note, and this solution seems to work in this case. However, I haven't been able apply it to a "thanks" note.

\documentclass[12pt,letterpaper,twocolumn]{article}
%\usepackage{bigfoot} % Moves the note to the left, but messes up the layout
\begin{document}

\title{Lorem ipsum}
\author{John Doe\thanks{
    Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor
    incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis
    nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi
    consequat. Quis aute iure reprehenderit in voluptate velit esse cillum
    dolore eu fugiat nulla pariatur. Excepteur sint obcaecat cupiditat non
    proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
    % Enable the following lines and the note fits in the left column.
    %Duis autem vel eum iriure dolor in hendrerit...
    }}

\maketitle

\begin{abstract}
Lorem ipsum
\end{abstract}

\section{First section}

Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor
incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud
exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute
iure reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla
pariatur. Excepteur sint obcaecat cupiditat non proident.

% Remove the first line, and the "thanks" note fits in the
% left column. Enable the second line, and it fits as well (!).
Duis autem
%vel eum iriure dolor in hendrerit...



\section{Second section}

\begin{figure}
A figure
\end{figure}

Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor
incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud
exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute
iure reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla
pariatur. Excepteur sint obcaecat cupiditat non proident.

\end{document}

Version is MiKTeX 2.9, the problem is identical for LaTeX and pdfTeX.

Answer 1

Without having this evaluated fully so far, it looks to me like a (known) deficiency in the LaTeX2e footnote handling if floats are part of the picture. The problem is that there is enough free space in the first column for LaTeX to read on until after the second section and the float flollowing it (without finishing the first column).

Now when LaTeX looks at this float it find that there is not enough space to put it into the first column. So it puts it on the deferlist and puts the text back to main vertical list for reprocessing. And there is the catch: The footnotes ended up a single box by that process (well here is only one, but assume you have several ones from several places on the page) Now these are reinserted as well but at the end of the accumulated text not in their original place. LaTeX makes the assumption that all the material it has seen will have space on the current page and will end there. This is normally true but not in your specific scenario.

In your case the the section 2 heading plus a line would fit into the first column, however only 1 line! But LaTeX prohibits breaking after the first text line after a section. So normally LaTeX would find out that it is not possible to put section2 + 2 lines into the first column and therefore would break before the section.

However, before LaTeX can detect this it sees your figure (directly after the heading) and therefore tries to place that figure and that moves the "thanks" after the section 2 heading. Only then it goes back and tried to typeset the first column and the section still doesn't fit with two lines after it, so it break before it but now your "thanks" are moved.

You can verify this by placing a \pagebreak into the first line after the section2. then this moves into the first column.

Alternatively, move the placement of the figure a bit after the heading. It is in fact not a good idea to have it directly after \section because of the special processing that the heading tries to do to the following paragraph.

Now this "is" a deficiency, but the 2e algorithm is so delicate that modifications here are not advisable.