Merge branch 'atom-xhtml-squashed' into 'master'

Fix invalid Atom feeds when using emoji, horizontal rules, or images

This is a fix for issues #880, #723, #1113.

Markdown must be rendered to XHTML, not HTML, when generating summary content for Atom feeds. Otherwise, content-less tags like *img* and *hr* are not terminated and make the Atom XML invalid. Such tags are generated when issue descriptions, merge request descriptions, comments, or commit messages use emoji, horizontal rules, or images.

To pass this option through from the relevant Haml templates to the proper place in the `gfm()` method, a new method `gfm_with_options()` is introduced. It reuses the options dictionary passed to `markdown()` and interprets options `xhtml` and `parse_tasks` from it (the latter was a convenient replacement for `gfm_with_tasks()`). `xhtml` is already interpreted by Redcarpet::Render::HTML, but that alone was not sufficient, because the post-processing in `gfm()` would convert its XHTML tags back to HTML.

I found no way of passing additional optional options to the existing `gfm()` method without requiring updates to existing callers and without getting in the way of the existing optional arguments, but maybe someone who knows more about Ruby than I can think of one.

Thorough review appreciated since this is the first time I have used Ruby.

See merge request !344

2 files changed, 23 insertions, 13 deletions

diff --git a/lib/gitlab/markdown.rb b/lib/gitlab/markdown.rb
index c3a8d90ef54..e02e5b9fc3d 100644
--- a/lib/gitlab/markdown.rb
+++ b/lib/gitlab/markdown.rb
@@ -34,17 +34,23 @@ module Gitlab
 
     attr_reader :html_options
 
-    def gfm_with_tasks(text, project = @project, html_options = {})
-      text = gfm(text, project, html_options)
-      parse_tasks(text)
+    # Public: Parse the provided text with GitLab-Flavored Markdown
+    #
+    # text         - the source text
+    # project      - extra options for the reference links as given to link_to
+    # html_options - extra options for the reference links as given to link_to
+    def gfm(text, project = @project, html_options = {})
+      gfm_with_options(text, {}, project, html_options)
     end
 
     # Public: Parse the provided text with GitLab-Flavored Markdown
     #
     # text         - the source text
+    # options      - parse_tasks: true - render tasks
+    #              - xhtml: true       - output XHTML instead of HTML
     # project      - extra options for the reference links as given to link_to
     # html_options - extra options for the reference links as given to link_to
-    def gfm(text, project = @project, html_options = {})
+    def gfm_with_options(text, options = {}, project = @project, html_options = {})
       return text if text.nil?
 
       # Duplicate the string so we don't alter the original, then call to_str
@@ -87,14 +93,22 @@ module Gitlab
       markdown_pipeline = HTML::Pipeline::Gitlab.new(filters).pipeline
 
       result = markdown_pipeline.call(text, markdown_context)
-      text = result[:output].to_html(save_with: 0)
+      saveoptions = 0
+      if options[:xhtml]
+        saveoptions |= Nokogiri::XML::Node::SaveOptions::AS_XHTML
+      end
+      text = result[:output].to_html(save_with: saveoptions)
 
       allowed_attributes = ActionView::Base.sanitized_allowed_attributes
       allowed_tags = ActionView::Base.sanitized_allowed_tags
 
-      sanitize text.html_safe,
-               attributes: allowed_attributes + %w(id class style),
-               tags: allowed_tags + %w(table tr td th)
+      text = sanitize text.html_safe,
+                      attributes: allowed_attributes + %w(id class style),
+                      tags: allowed_tags + %w(table tr td th)
+      if options[:parse_tasks]
+        text = parse_tasks(text)
+      end
+      text
     end
 
     private
diff --git a/lib/redcarpet/render/gitlab_html.rb b/lib/redcarpet/render/gitlab_html.rb
index 1cd3933e4b7..10efff2ae9f 100644
--- a/lib/redcarpet/render/gitlab_html.rb
+++ b/lib/redcarpet/render/gitlab_html.rb
@@ -67,10 +67,6 @@ class Redcarpet::Render::GitlabHTML < Redcarpet::Render::HTML
     unless @template.instance_variable_get("@project_wiki") || @project.nil?
       full_document = h.create_relative_links(full_document)
     end
-    if @options[:parse_tasks]
-      h.gfm_with_tasks(full_document)
-    else
-      h.gfm(full_document)
-    end
+    h.gfm_with_options(full_document, @options)
   end
 end