mdwn: Automatically detect which libdiscount flags to use

[git.ikiwiki.info.git] / IkiWiki / Plugin / mdwn.pm

diff --git a/IkiWiki/Plugin/mdwn.pm b/IkiWiki/Plugin/mdwn.pm
index 66116ae014f7a94cd8bda230514258bbb75acf42..eefa29a9711204541c52b2c83fa959103fc05e67 100644 (file)
--- a/IkiWiki/Plugin/mdwn.pm
+++ b/IkiWiki/Plugin/mdwn.pm
@@ -89,6 +89,55 @@ sub htmlize (@) {
                    (! exists $config{nodiscount} || ! $config{nodiscount})) {
                        eval q{use Text::Markdown::Discount};
                        if (! $@) {
+                               my $markdown = \&Text::Markdown::Discount::markdown;
+                               my $always_flags = 0;
+
+                               # Disable Pandoc-style % Title, % Author, % Date
+                               # Use the meta plugin instead
+                               $always_flags |= Text::Markdown::Discount::MKD_NOHEADER();
+
+                               # Disable Unicodification of quote marks, em dashes...
+                               # Use the typography plugin instead
+                               $always_flags |= Text::Markdown::Discount::MKD_NOPANTS();
+
+                               # Workaround for discount's eliding of <style> blocks.
+                               # https://rt.cpan.org/Ticket/Display.html?id=74016
+                               if (Text::Markdown::Discount->can('MKD_NOSTYLE')) {
+                                       $always_flags |= Text::Markdown::Discount::MKD_NOSTYLE();
+                               }
+                               elsif ($markdown->('<style>x</style>', 0) !~ '<style>' &&
+                                       $markdown->('<style>x</style>', 0x00400000) =~ m{<style>x</style>}) {
+                                       $always_flags |= 0x00400000;
+                               }
+
+                               # Enable fenced code blocks in libmarkdown >= 2.2.0
+                               # https://bugs.debian.org/888055
+                               if (Text::Markdown::Discount->can('MKD_FENCEDCODE')) {
+                                       $always_flags |= Text::Markdown::Discount::MKD_FENCEDCODE();
+                               }
+                               elsif ($markdown->("~~~\nx\n~~~", 0) !~ m{<pre\b} &&
+                                       $markdown->("~~~\nx\n~~~", 0x02000000) =~ m{<pre\b}) {
+                                       $always_flags |= 0x02000000;
+                               }
+
+                               # PHP Markdown Extra-style term\n: definition -> <dl>
+                               if (Text::Markdown::Discount->can('MKD_DLEXTRA')) {
+                                       $always_flags |= Text::Markdown::Discount::MKD_DLEXTRA();
+                               }
+                               elsif ($markdown->("term\n: def\n", 0) !~ m{<dl>} &&
+                                       $markdown->("term\n: def\n", 0x01000000) =~ m{<dl>}) {
+                                       $always_flags |= 0x01000000;
+                               }
+
+                               # Allow dashes and underscores in tag names
+                               if (Text::Markdown::Discount->can('MKD_GITHUBTAGS')) {
+                                       $always_flags |= Text::Markdown::Discount::MKD_GITHUBTAGS();
+                               }
+                               elsif ($markdown->('<foo_bar>', 0) !~ m{<foo_bar} &&
+                                       $markdown->('<foo_bar>', 0x08000000) =~ m{<foo_bar\b}) {
+                                       $always_flags |= 0x08000000;
+                               }
+
                                $markdown_sub=sub {
                                        my $t=shift;
 
@@ -96,15 +145,7 @@ sub htmlize (@) {
                                        # https://rt.cpan.org/Ticket/Display.html?id=73657
                                        return "" if $t=~/^\s*$/;
 
-                                       my $flags=0;
-
-                                       # Disable Pandoc-style % Title, % Author, % Date
-                                       # Use the meta plugin instead
-                                       $flags |= Text::Markdown::Discount::MKD_NOHEADER();
-
-                                       # Disable Unicodification of quote marks, em dashes...
-                                       # Use the typography plugin instead
-                                       $flags |= Text::Markdown::Discount::MKD_NOPANTS();
+                                       my $flags=$always_flags;
 
                                        if ($config{mdwn_footnotes}) {
                                                $flags |= Text::Markdown::Discount::MKD_EXTRA_FOOTNOTE();
@@ -114,42 +155,6 @@ sub htmlize (@) {
                                                $flags |= Text::Markdown::Discount::MKD_NOALPHALIST();
                                        }
 
-                                       # Workaround for discount's eliding
-                                       # of <style> blocks.
-                                       # https://rt.cpan.org/Ticket/Display.html?id=74016
-                                       if (Text::Markdown::Discount->can("MKD_NOSTYLE")) {
-                                               $flags |= Text::Markdown::Discount::MKD_NOSTYLE();
-                                       }
-                                       else {
-                                               # This is correct for the libmarkdown.so.2 ABI
-                                               $flags |= 0x00400000;
-                                       }
-
-                                       # Enable fenced code blocks in libmarkdown >= 2.2.0
-                                       # https://bugs.debian.org/888055
-                                       if (Text::Markdown::Discount->can("MKD_FENCEDCODE")) {
-                                               $flags |= Text::Markdown::Discount::MKD_FENCEDCODE();
-                                       }
-                                       else {
-                                               $flags |= 0x02000000;
-                                       }
-
-                                       # PHP Markdown Extra-style term\n: definition -> <dl>
-                                       if (Text::Markdown::Discount->can("MKD_DLEXTRA")) {
-                                               $flags |= Text::Markdown::Discount::MKD_DLEXTRA();
-                                       }
-                                       else {
-                                               $flags |= 0x01000000;
-                                       }
-
-                                       # Allow dashes and underscores in tag names
-                                       if (Text::Markdown::Discount->can("MKD_GITHUBTAGS")) {
-                                               $flags |= Text::Markdown::Discount::MKD_GITHUBTAGS();
-                                       }
-                                       else {
-                                               $flags |= 0x08000000;
-                                       }
-
                                        return Text::Markdown::Discount::markdown($t, $flags);
                                }
                        }