[PATCH -perfbook 3/4] cleverefcheck.pl: Add test of \begin{...} next to epigraph

[Akira Yokosawa <akiyks@xxxxxxxxx>]

If a section heading has an epigraph next to it and an
environment of some sort follows the epigraph, the behavior
of a proper LaTeX heading is lost.

Add tests to detect such potential break patterns following
epigraphs.

Notes:
  o "Any environment" does not include "fcvref".
  o "listing" is caught by other tests for it.
  o glossary.tex has "description" list next to its epigraph.
    As it is at the head of an appendix and won't cause
    page/colum break, it is ignored.

Signed-off-by: Akira Yokosawa <akiyks@xxxxxxxxx>
---
 utilities/cleverefcheck.pl | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/utilities/cleverefcheck.pl b/utilities/cleverefcheck.pl
index 74ac9d72..6e9a59e8 100755
--- a/utilities/cleverefcheck.pl
+++ b/utilities/cleverefcheck.pl
@@ -28,10 +28,12 @@ my $acr_ptn = qr/(^|\s+)[aA]cr[^\s\{]*{/ ;
 my $heading_ptn = qr/(\\chapter|\\section|\\subsection|\\subsubsection)/ ;
 my $listing_ptn = qr/\\begin\{(listing|Verbatim)/ ;
 my $qqa_ptn = qr/\\E?QuickQuizAnswer[BEM]?/ ;
+my $epig_ptn = qr/\\[Ee]pigraph/ ;
 my $in_footnote = 0 ;
 my $footnote_save = 0;
 my $after_heading = 0;
 my $after_qqa = 0;
+my $after_epig = 0;
 
 sub check_line {
     my $raw_line = $line;
@@ -117,6 +119,7 @@ sub check_line {
 	if ($line =~ /$listing_ptn/) {
 	    print $ARGV[0], ':', $line_num, ':', $raw_line, "^^^ listing next to heading ^^^\n";
 	    $after_heading = 0 ;
+	    $after_epig = 0 ;  # after epigraph or not does not matter for listing
 	}
     }
     if ($after_qqa) {
@@ -131,6 +134,15 @@ sub check_line {
 	    $after_qqa = 0;
 	}
     }
+    if ($after_epig) {
+	if ($line =~ /^\s*$/) {  # empty line ends epigraph
+	    $after_epig -= 1 ;
+	}
+	if ($line =~ /^\s*\\begin/ && $line !~ /(fcvref|listing)/) {
+	    print $ARGV[0], ':', $line_num, ':', $raw_line, "^^^ environment next to epigraph ^^^\n";
+	    $after_epig = 0 ;
+	}
+    }
     if ($line =~ /$Verbatim_end/) {
 	$skip = 0;
     } else {
@@ -170,6 +182,9 @@ sub check_line {
     if ($line =~ /$qqa_ptn/) {
 	$after_qqa = 1 ;
     }
+    if ($line =~ /$epig_ptn/ && $ARGV[0] !~ /glossary\.tex/) { # exempt glossary.tex
+	$after_epig = 2 ;
+    }
 }
 
 open(my $fh, '<:encoding(UTF-8)', $ARGV[0])
-- 
2.17.1