[PATCH -perfbook 0/4] Address potential widowing of headings

[Akira Yokosawa <akiyks@gmail.com>]

Hi Paul,

There was some confusion on my side WRT undesired page/column
breaks.

While testing the added checks in cleverefcheck.pl, I saw too
many potential such cases flagged.  This made me do some tests
to reproduce unfortunate page/column breaks.

There are three such patterns I have confirmed.

1. "listing" environment (with contents of fancyvrb) next to proper
LaTeX headings (\chapter, \section, \subsection, etc.)

2. Any environment (not necessarily float) next to QQA heading
of "Answer:"

3. Any environment (not necessarily float) next to epigraph

This means commit f106e0e6dc43 ("defer/rcuusage: Move float objects
away of section titles") has no merit.  It is safe to revert it if
you'd like.  I was confused by patterns 2 and 3 and thought that
floating objects can cause undesired breaks. 

Patches 1/4--3/4 add tests in cleverefcheck.pl that check patterns
listed above respectively.

Patch 4/4 fixes problematic places flagged by the updated script.
Feel free to wordsmith the leading phrases I added in QQAs.

        Thanks, Akira
--
Akira Yokosawa (4):
  cleverefcheck.pl: Add test of listing next to heading
  cleverefcheck.pl: Add test of \begin{...} at head of QQA
  cleverefcheck.pl: Add test of \begin{...} next to epigraph
  treewide: Address potential widowing of headings

 appendix/questions/after.tex  |  4 +++
 datastruct/datastruct.tex     | 14 +++++-----
 defer/refcnt.tex              | 24 ++++++++---------
 formal/axiomatic.tex          | 22 +++++++--------
 locking/locking-existence.tex |  9 ++++---
 memorder/memorder.tex         |  6 ++---
 utilities/cleverefcheck.pl    | 50 +++++++++++++++++++++++++++++++++++
 7 files changed, 92 insertions(+), 37 deletions(-)


base-commit: f106e0e6dc436683bb119dd8992c6f173994d182
-- 
2.17.1