From b5801a65807017ac784979afd9dd451fa6c7c16c Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Thu, 25 Jan 2024 20:26:22 +0100
Subject: [PATCH] font: html encode control characters

Replace unintended commands (i.e. tab, newline) by rendered glyphs if
declared by a font, such as C1 characters following CP-1252 in Unifont.
---
 font.plp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/font.plp b/font.plp
index a460144..a9f3491 100644
--- a/font.plp
+++ b/font.plp
@@ -156,12 +156,13 @@ EOT
 		my ($class, $name, $mnem, $entity, $string) = @{$info};
 		my $np = $class =~ /\bC\S\b/;  # noprint if control or invalid
 		# display literal character, with placeholder circle if non-spacing/enclosing
-		my $html = ($class =~ /\bM[ne]\b/ && chr 9676) . EscapeHTML(chr $cp);
+		my $html = $np ? !!$cover{$cp} && sprintf("&#%d;", $cp) :
+			($class =~ /\bM[ne]\b/ && chr 9676) . EscapeHTML(chr $cp);
 		say sprintf '<td class="%s" title="U+%04X%s">%s',
 			!$class ? ('l0', $cp, '', '') : (
 			$cover{$cp} ? $np ? 'l2' : 'l5' : $np ? 'Xi' : 'l1',
 			$cp, !!$name && ": $name",
-			($cover{$cp} || !$np) && $html
+			$html
 			);
 	}
 	say '</table>';
-- 
2.30.0