gnu: Add perl-text-markdown-discount.

* gnu/packages/markdown.scm (perl-text-markdown-discount): New variable.
* gnu/packages/patches/perl-text-markdown-discount-use-system-markdown.patch:
  New file.

gnu/packages/markup.scm

@@ -26,7 +26,9 @@ (define-module (gnu packages markup)
   #:use-module (guix build-system gnu)
   #:use-module (guix build-system trivial)
   #:use-module (guix build-system cmake)
+  #:use-module (guix build-system perl)
   #:use-module (gnu packages compression)
+  #:use-module (gnu packages)
   #:use-module (gnu packages perl)
   #:use-module (gnu packages python)
   #:use-module (gnu packages web))
@@ -144,6 +146,50 @@ (define-public discount
     (home-page "http://www.pell.portland.or.us/~orc/Code/discount/")
     (license bsd-3)))
 
+(define-public perl-text-markdown-discount
+  (package
+    (name "perl-text-markdown-discount")
+    (version "0.11")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append
+             "mirror://cpan/authors/id/S/SE/SEKIMURA/Text-Markdown-Discount-"
+             version
+             ".tar.gz"))
+       (sha256
+        (base32
+         "1xx7v3wnla7m6wa3h33whxw3vvincaicg4yra1b9wbzf2aix9rnw"))
+       (patches
+        (search-patches "perl-text-markdown-discount-use-system-markdown.patch"))))
+    (build-system perl-build-system)
+    (arguments
+     `(#:phases
+       (modify-phases %standard-phases
+         (add-before 'build 'set-ldflags
+           (lambda* (#:key inputs #:allow-other-keys)
+             (substitute* "Makefile"
+               (("OTHERLDFLAGS = ")
+                (string-append
+                      "OTHERLDFLAGS = -lmarkdown -Wl,-rpath="
+                      (assoc-ref inputs "discount")
+                      "/lib"))))))))
+    (inputs
+     `(("discount" ,discount)))
+    (home-page
+     "http://search.cpan.org/dist/Text-Markdown-Discount")
+    (synopsis
+     "Fast function for converting Markdown to HTML using Discount")
+    (description
+     "Text::Markdown::Discount is a Perl extension to the Discount markdown
+implementation.
+
+@example
+  use Text::Markdown::Discount;
+  my $html = markdown($text)
+@end example")
+    (license perl-license)))
+
 (define-public cmark
   (package
     (name "cmark")

gnu/packages/patches/perl-text-markdown-discount-use-system-markdown.patch

@@ -0,0 +1,32 @@
+Description: Use the markdown library provided by the libmarkdown2 package.
+Author: Alessandro Ghedini <al3xbio@gmail.com>
+Origin: vendor
+Forwarded: not-needed
+Last-Update: 2012-01-01
+
+--- a/Makefile.PL
++++ b/Makefile.PL
+@@ -57,12 +57,6 @@
+ 
+ 
+ 
+-sub MY::postamble {
+-    return sprintf('
+-$(MYEXTLIB):
+-	%s
+-', qq{( cd $extdir; CC='cc -fPIC' sh configure.sh; make )\n});
+-}
+ 
+ WriteMakefile(
+     NAME              => 'Text::Markdown::Discount',
+@@ -71,8 +65,6 @@
+     ($] >= 5.005 ?
+       (ABSTRACT_FROM  => 'lib/Text/Markdown/Discount.pm',
+        AUTHOR         => 'Masayoshi Sekimura <sekimura@cpan.org>') : ()),
+-    LIBS               => '-L' . $extdir,
+-    INC               => '-I. -I' . $extdir,
+-    MYEXTLIB          => $myextlib,
+-    clean             => { FILES => $clean_files },
++    LIBS               => '-lmarkdown',
++    INC               => '-I.',
+ );