Fix passing multiline params to include tag when using the variable syntax (#6858)

Merge pull request 6858

lib/jekyll/tags/include.rb

@@ -19,7 +19,7 @@ module Jekyll
       VARIABLE_SYNTAX = %r!
         (?<variable>[^{]*(\{\{\s*[\w\-\.]+\s*(\|.*)?\}\}[^\s{}]*)+)
         (?<params>.*)
-      !x
+      !mx
 
       FULL_VALID_SYNTAX = %r!\A\s*(?:#{VALID_SYNTAX}(?=\s|\z)\s*)*\z!
       VALID_FILENAME_CHARS = %r!^[\w/\.-]+$!

test/test_tags.rb

@@ -948,6 +948,64 @@ CONTENT
       end
     end
 
+    context "with simple syntax but multiline markup" do
+      setup do
+        content = <<CONTENT
+---
+title: Include tag parameters
+---
+
+{% include sig.markdown myparam="test" %}
+
+{% include params.html
+  param="value" %}
+CONTENT
+        create_post(content, {
+          "permalink"   => "pretty",
+          "source"      => source_dir,
+          "destination" => dest_dir,
+          "read_posts"  => true,
+        })
+      end
+
+      should "correctly output include variable" do
+        assert_match "<span id=\"include-param\">value</span>", @result.strip
+      end
+
+      should "ignore parameters if unused" do
+        assert_match "<hr />\n<p>Tom Preston-Werner\ngithub.com/mojombo</p>\n", @result
+      end
+    end
+
+    context "with variable syntax but multiline markup" do
+      setup do
+        content = <<CONTENT
+---
+title: Include tag parameters
+---
+
+{% include sig.markdown myparam="test" %}
+{% assign path = "params" | append: ".html" %}
+{% include {{ path }}
+  param="value" %}
+CONTENT
+        create_post(content, {
+          "permalink"   => "pretty",
+          "source"      => source_dir,
+          "destination" => dest_dir,
+          "read_posts"  => true,
+        })
+      end
+
+      should "correctly output include variable" do
+        assert_match "<span id=\"include-param\">value</span>", @result.strip
+      end
+
+      should "ignore parameters if unused" do
+        assert_match "<hr />\n<p>Tom Preston-Werner\ngithub.com/mojombo</p>\n", @result
+      end
+    end
+
     context "with invalid parameter syntax" do
       should "throw a ArgumentError" do
         content = <<CONTENT