gnu: Add font-mathjax.

* gnu/packages/fonts.scm (font-mathjax): New variable.

gnu/packages/fonts.scm

@@ -19,6 +19,7 @@
 ;;; Copyright © 2017 Alex Griffin <a@ajgrf.com>
 ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
 ;;; Copyright © 2017 Brendan Tildesley <brendan.tildesley@openmailbox.org>
+;;; Copyright © 2017 Arun Isaac <arunisaac@systemreboot.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -1227,3 +1228,42 @@ Ensuring readability and clarity at both large and small sizes, these icons
 have been optimized for beautiful display on all common platforms and display
 resolutions.")
    (license license:asl2.0)))
+
+(define-public font-mathjax
+  (package
+    (name "font-mathjax")
+    (version "2.7.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append
+             "https://github.com/mathjax/MathJax/archive/"
+             version ".tar.gz"))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32
+         "0sbib5lk0jrvbq6s72ag6ss3wjlz5wnk07ddxij1kp96yg3c1d1b"))))
+    (build-system trivial-build-system)
+    (arguments
+     `(#:modules ((guix build utils))
+       #:builder
+       (begin
+         (use-modules (guix build utils)
+                      (ice-9 match))
+         (set-path-environment-variable
+          "PATH" '("bin") (map (match-lambda
+                                 ((_ . input)
+                                  input))
+                               %build-inputs))
+         (let ((install-directory (string-append %output "/share/fonts/mathjax")))
+           (mkdir-p install-directory)
+           (zero? (system* "tar" "-C" install-directory "-xvf"
+                           (assoc-ref %build-inputs "source")
+                           "MathJax-2.7.1/fonts" "--strip" "2"))))))
+    (native-inputs
+     `(("gzip" ,gzip)
+       ("tar" ,tar)))
+    (home-page "https://www.mathjax.org/")
+    (synopsis "Fonts for MathJax")
+    (description "This package contains the fonts required for MathJax.")
+    (license license:asl2.0)))