mdwn: Enable footnotes by default when using Discount

A new mdwn_footnotes option can be used to disable footnotes in
MultiMarkdown and Discount.

IkiWiki/Plugin/mdwn.pm

@@ -7,6 +7,7 @@ use strict;
 use IkiWiki 3.00;
 
 sub import {
+	hook(type => "checkconfig", id => "mdwn", call => \&checkconfig);
 	hook(type => "getsetup", id => "mdwn", call => \&getsetup);
 	hook(type => "htmlize", id => "mdwn", call => \&htmlize, longname => "Markdown");
 	hook(type => "htmlize", id => "md", call => \&htmlize, longname => "Markdown (popular file extension)", nocreate => 1);
@@ -33,6 +34,17 @@ sub getsetup () {
 			safe => 1,
 			rebuild => 1,
 		},
+		mdwn_footnotes => {
+			type => "boolean",
+			example => 1,
+			description => "enable footnotes in Markdown (where supported)?",
+			safe => 1,
+			rebuild => 1,
+		},
+}
+
+sub checkconfig () {
+	$config{mdwn_footnotes} = 1 unless defined $config{mdwn_footnotes};
 }
 
 my $markdown_sub;
@@ -54,7 +66,13 @@ sub htmlize (@) {
 			}
 			else {
 				$markdown_sub=sub {
-					Text::MultiMarkdown::markdown(shift, {use_metadata => 0});
+					my %flags=( use_metadata => 0 );
+
+					if ($config{mdwn_footnotes}) {
+						$flags{disable_footnotes}=1;
+					}
+
+					Text::MultiMarkdown::markdown(shift, \%flags);
 				}
 			}
 		}
@@ -79,6 +97,10 @@ sub htmlize (@) {
 					# Use the typography plugin instead
 					$flags |= Text::Markdown::Discount::MKD_NOPANTS();
 
+					if ($config{mdwn_footnotes}) {
+						$flags |= Text::Markdown::Discount::MKD_EXTRA_FOOTNOTE();
+					}
+
 					# Workaround for discount's eliding
 					# of <style> blocks.
 					# https://rt.cpan.org/Ticket/Display.html?id=74016

debian/changelog

@@ -8,6 +8,9 @@ ikiwiki (3.20170112) UNRELEASED; urgency=medium
     a set-but-empty name as if they were not signed in.
   * When the CGI fails, print the error to stderr, not "Died"
   * mdwn: Don't mangle <style> into <elyts> under some circumstances
+  * mdwn: Enable footnotes by default when using the default Discount
+    implementation. A new mdwn_footnotes option can be used to disable
+    footnotes in MultiMarkdown and Discount.
 
  -- Simon McVittie <smcv@debian.org>  Sun, 14 May 2017 15:34:52 +0100
 

doc/bugs/footnotes-look-weird.mdwn

@@ -92,6 +92,10 @@ screen readers), as detailed in [this Stack Overflow discussion][].
 >>> --[[smcv]]
 >>>
 >>>> Makes perfect sense to me. --[[anarcat]]
+>>>>
+>>>>> I have now enabled footnotes in Discount by default, with a new
+>>>>> `mdwn_footnotes` option that can switch them off if they become
+>>>>> problematic. --[[smcv]]
 >>>
 >> For example, to enable footnotes, one needs to call Discount like this:
 >>