Filter entries in the collection per EntryFilter#filter

lib/jekyll/collection.rb

@@ -25,16 +25,34 @@ module Jekyll
     #
     # Returns the sorted array of docs.
     def read
-      Dir.glob(File.join(directory, "**", "*.*")).each do |file_path|
-        if allowed_document?(file_path)
-          doc = Jekyll::Document.new(file_path, { site: site, collection: self })
-          doc.read
-          docs << doc
-        end
+      filtered_entries.each do |file_path|
+        doc = Jekyll::Document.new(Jekyll.sanitized_path(directory, file_path), { site: site, collection: self })
+        doc.read
+        docs << doc
       end
       docs.sort!
     end
 
+    # All the entries in this collection.
+    #
+    # Returns an Array of file paths to the documents in this collection
+    #   relative to the collection's directory
+    def entries
+      Dir.glob(File.join(directory, "**", "*.*")).map do |entry|
+        entry[File.join(directory, "")] = ''; entry
+      end
+    end
+
+    # Filtered version of the entries in this collection.
+    # See `Jekyll::EntryFilter#filter` for more information.
+    #
+    # Returns a list of filtered entry paths.
+    def filtered_entries
+      Dir.chdir(directory) do
+        entry_filter.filter(entries)
+      end
+    end
+
     # The directory for this Collection, relative to the site source.
     #
     # Returns a String containing the directory name where the collection
@@ -51,14 +69,12 @@ module Jekyll
       Jekyll.sanitized_path(site.source, relative_directory)
     end
 
-    # Determine whether the document at a given path is an allowed document.
+    # The entry filter for this collection.
+    # Creates an instance of Jekyll::EntryFilter.
     #
-    # path - the path to the document within this collection
-    #
-    # Returns false if the site is in safe mode and the document is a symlink,
-    #   true otherwise.
-    def allowed_document?(path)
-      !(site.safe && File.symlink?(path))
+    # Returns the instance of Jekyll::EntryFilter for this collection.
+    def entry_filter
+      @entry_filter ||= Jekyll::EntryFilter.new(site, relative_directory)
     end
 
     # An inspect string.

lib/jekyll/document.rb

@@ -193,12 +193,12 @@ module Jekyll
     #
     # Returns a Hash representing this Document's data.
     def to_liquid
-      data.merge({
+      Utils.deep_merge_hashes data, {
         "content"       => content,
         "path"          => path,
         "relative_path" => relative_path,
         "url"           => url
-      })
+      }
     end
 
     # The inspect string for this document.

test/source/_methods/_do_not_read_me.md

@@ -0,0 +1,5 @@
+---
+title: The unreadable wonder
+---
+
+Don't read me, you fool! FILTER ME

test/source/_methods/site/_dont_include_me_either.md

@@ -0,0 +1,5 @@
+---
+title: Don't Include Me Either
+---
+
+Don't include me either. FILTER ME PLZ

test/test_collections.rb

@@ -68,6 +68,7 @@ class TestCollections < Test::Unit::TestCase
         "collections" => ["methods"]
       })
       @site.process
+      @collection = @site.collections["methods"]
     end
 
     should "create a Hash on Site with the label mapped to the instance of the Collection" do
@@ -89,6 +90,19 @@ class TestCollections < Test::Unit::TestCase
         ], doc.relative_path
       end
     end
+
+    should "not include files which start with an underscore in the base collection directory" do
+      assert_not_include @collection.filtered_entries, "_do_not_read_me.md"
+    end
+
+    should "not include files which start with an underscore in a subdirectory" do
+      assert_not_include @collection.filtered_entries, "site/_dont_include_me_either.md"
+    end
+
+    should "not include the underscored files in the list of docs" do
+      assert_not_include @collection.docs.map(&:relative_path), "_methods/_do_not_read_me.md"
+      assert_not_include @collection.docs.map(&:relative_path), "_methods/site/_dont_include_me_either.md"
+    end
   end
 
   context "in safe mode" do
@@ -102,11 +116,11 @@ class TestCollections < Test::Unit::TestCase
     end
 
     should "not allow symlinks" do
-      assert !@collection.allowed_document?(File.join(@collection.directory, "um_hi.md"))
+      assert_not_include @collection.filtered_entries, "um_hi.md"
     end
 
     should "not include the symlinked file in the list of docs" do
-      assert_not_include %w[_methods/um_hi.md], @collection.docs.map(&:relative_path)
+      assert_not_include @collection.docs.map(&:relative_path), "_methods/um_hi.md"
     end
   end