fixed mediawiki link handling

lib/gollum/markup.rb

@@ -13,6 +13,7 @@ module Gollum
       @name    = page.filename
       @data    = page.text_data
       @version = page.version.id
+      @format  = page.format
       @dir     = ::File.dirname(page.path)
       @tagmap  = {}
       @codemap = {}
@@ -294,10 +295,14 @@ module Gollum
     # Returns the String HTML if the tag is a valid page link tag or nil
     #   if it is not.
     def process_page_link_tag(tag, no_follow = false)
-      parts = tag.split('|')
+      parts = if @format == :mediawiki
-      name  = parts[0].strip
+                tag.split('|').reverse
-      cname = @wiki.page_class.cname((parts[1] || parts[0]).strip)
+              else
-      tag = if name =~ %r{^https?://} && parts[1].nil?
+                tag.split('|')
+              end
+      name, page_name = *parts.compact.map(&:strip)
+      cname = @wiki.page_class.cname(page_name || name)
+      tag = if name =~ %r{^https?://} && page_name.nil?
               %{<a href="#{name}">#{name}</a>}
             else
               presence    = "absent"

test/test_markup.rb

@@ -169,6 +169,13 @@ context "Markup" do
     assert_equal "<p>a <a class=\"internal present\" href=\"/Potato\">Potato Heaad</a></p>", output
   end
 
+  test "page link with different text on mediawiki" do
+    @wiki.write_page("Potato", :mediawiki, "a [[Potato|Potato Heaad]] ", commit_details)
+    page = @wiki.page("Potato")
+    output = page.formatted_data
+    assert_equal "<p>\na <a class=\"internal present\" href=\"/Potato\">Potato Heaad</a> \n</p>", output
+  end
+
   #########################################################################
   #
   # Images