From 2b57795c7f24fb8be7a5d165d08e0a29de64f938 Mon Sep 17 00:00:00 2001
From: Pat Hawks <pat@pathawks.com>
Date: Thu, 14 Jul 2016 13:08:25 -0500
Subject: [PATCH 1/2] Failing test: where_exp filter should filter posts

---
 test/test_filters.rb | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test/test_filters.rb b/test/test_filters.rb
index fa0f9e52..1c5b27c6 100644
--- a/test/test_filters.rb
+++ b/test/test_filters.rb
@@ -594,6 +594,14 @@ class TestFilters < JekyllUnitTest
         assert_equal "b", results[1]["id"]
         assert_equal "d", results[2]["id"]
       end
+
+      should "filter posts" do
+        site = fixture_site.tap(&:read)
+        posts = site.site_payload["site"]["posts"]
+        results = @filter.where_exp(posts, "obj", "obj.title == 'Foo Bar'")
+        assert_equal 1, results.length
+        assert_equal site.posts.find { |p| p.title == "Foo Bar" }, results.first
+      end
     end
 
     context "sort filter" do

From 99663a919966e9f2f204b048f180e441f7a4bd32 Mon Sep 17 00:00:00 2001
From: Florian Thomas <flo@florianthomas.net>
Date: Sun, 10 Jul 2016 20:52:39 +0200
Subject: [PATCH 2/2] object needs to respond to select instead of being an
 enumerable

---
 lib/jekyll/filters.rb |  8 ++++----
 test/test_filters.rb  | 14 ++++++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/lib/jekyll/filters.rb b/lib/jekyll/filters.rb
index 231eb7b6..f98845d2 100644
--- a/lib/jekyll/filters.rb
+++ b/lib/jekyll/filters.rb
@@ -233,11 +233,11 @@ module Jekyll
     #
     # Returns the filtered array of objects
     def where(input, property, value)
-      return input unless input.is_a?(Enumerable)
+      return input unless input.respond_to?(:select)
       input = input.values if input.is_a?(Hash)
       input.select do |object|
         Array(item_property(object, property)).map(&:to_s).include?(value.to_s)
-      end
+      end || []
     end
 
     # Filters an array of objects against an expression
@@ -248,7 +248,7 @@ module Jekyll
     #
     # Returns the filtered array of objects
     def where_exp(input, variable, expression)
-      return input unless input.is_a?(Enumerable)
+      return input unless input.respond_to?(:select)
       input = input.values if input.is_a?(Hash) # FIXME
 
       condition = parse_condition(expression)
@@ -257,7 +257,7 @@ module Jekyll
           @context[variable] = object
           condition.evaluate(@context)
         end
-      end
+      end || []
     end
 
     # Sort an array of objects
diff --git a/test/test_filters.rb b/test/test_filters.rb
index 1c5b27c6..b6effecd 100644
--- a/test/test_filters.rb
+++ b/test/test_filters.rb
@@ -15,6 +15,10 @@ class TestFilters < JekyllUnitTest
     end
   end
 
+  class SelectDummy
+    def select; end
+  end
+
   context "filters" do
     setup do
       @filter = JekyllFilter.new({
@@ -530,6 +534,11 @@ class TestFilters < JekyllUnitTest
         assert_equal 1, results.length
         assert_equal 4.7, results[0]["rating"]
       end
+
+      should "always return an array if the object responds to `select`" do
+        results = @filter.where(SelectDummy.new, "obj", "1 == 1")
+        assert_equal [], results
+      end
     end
 
     context "where_exp filter" do
@@ -602,6 +611,11 @@ class TestFilters < JekyllUnitTest
         assert_equal 1, results.length
         assert_equal site.posts.find { |p| p.title == "Foo Bar" }, results.first
       end
+
+      should "always return an array if the object responds to `select`" do
+        results = @filter.where_exp(SelectDummy.new, "obj", "1 == 1")
+        assert_equal [], results
+      end
     end
 
     context "sort filter" do