Still on footnotes

Still on footnotes

[Giuseppe Bilotta]

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[Using the latest ConTeXt]

Hello, I noticed that there are still a couple of problems
with footnotes in ConTeXt.

The first one is the fact that sometimes body text flows in the
footnote space, thus overprinting existing footnotes. After some
debugging, I think I found that it happens only in a very particular
case: when using footnotes inside columns, without having footnotes
after the column.

Precisely, if there is a footnote in the columns, and the columns
end before the end of the page, and there is non-column text without
footnotes, the footnote from the columns is overprinted by the text
after the column. If, on the other hand, there *are* footnotes in the
post-column text, then the footnotes are all placed correctly
(both the in-column and post-column footnotes) and text doesn't
overprint footnotes. Since the presence of post-column footnotes
allows the correct placement also of in-column footnotes, I believe
that the overprint can be prevented also when there are no post-column
footnotes, if the output routines do an appropriate check.

[see attached file footbug1.tex for error details: commenting the
second footnote shows the bug]

The second problem is that sometimes the footnote text ends up
in the wrong page. This happens mostly when long footnotes happen
near the end of the page, and the size of paragraph+footnote is bigger
than would fit in the page, while the paragraph alone would: in such
a case the paragraph is not split, nor does it migrate to the next
page (to prevent underfull boxes), thus giving the awfull effect of the
footnote number at the end of a page and the relative footnote
text on the next page, which is IMHO worse than the underfull box
that might result from migrating the whole paragraph.

[see attached file footbug2.tex for two examples of such errors]

Giuseppe Bilotta

[-- Attachment #2: footbug1.tex --]
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\setupindenting[medium]

\starttext

\input knuth

\blank

\input zapf

\blank

\startcolumns
\input tufte\footnote{This was a text from Tufte.}
\stopcolumns

\blank

\input tufte\footnote{This was a text from Tufte.}

\blank

\input knuth

\stoptext

[-- Attachment #3: footbug2.tex --]
[-- Type: application/octet-stream, Size: 734 bytes --]

\setupindenting[medium]

\starttext

\input knuth

\blank

\input zapf

\blank

\startcolumns
\input tufte\footnote{This was a text from Tufte. Let's now get
this footnote a little longer, so as to trigger the second bug. We
need at least two lines, maybe three of four\dots}
\stopcolumns

\blank

\input tufte\footnote{\input zapf }

\blank

\input knuth

\page[yes]

\input knuth

\blank

\input zapf

\blank

\startcolumns
\input tufte
\stopcolumns

\blank

You don't need another footnote to trigger the bug: just
enough text to push the last line of the problematic
paragraph to the end of the page.

\input tufte\footnote{\input zapf }

\blank

\input knuth




\stoptext