Empty permalink now shows an error

lib/jekyll/convertible.rb

@@ -61,6 +61,10 @@ module Jekyll
         Jekyll.logger.abort_with "Fatal:", "Invalid YAML front matter in #{File.join(base, name)}"
       end
 
+      unless valid_permalink?(self.data['permalink'])
+        Jekyll.logger.error "Error:", "Invalid permalink in #{File.join(base, name)}"
+      end
+
       self.data
     end
 
@@ -266,6 +270,15 @@ module Jekyll
       Jekyll::Hooks.trigger hook_owner, :post_render, self
     end
 
+    # Check data permalink
+    #
+    # permalink - the data permalink
+    #
+    # Returns true if the permalink is valid, false if otherwise
+    def valid_permalink?(permalink)
+      permalink.nil? || permalink.length > 0
+    end
+
     # Write the generated page file to the destination directory.
     #
     # dest - The String path to the destination dir.

test/fixtures/empty_permalink.erb

@@ -0,0 +1,4 @@
+---
+permalink: ''
+---
+Empty Permalink

test/test_convertible.rb

@@ -49,5 +49,14 @@ class TestConvertible < JekyllUnitTest
       assert_match(/invalid byte sequence in UTF-8/, out)
       assert_match(/#{File.join(@base, name)}/, out)
     end
+
+    should "parse the front-matter but show an error if permalink is empty" do
+      name = 'empty_permalink.erb'
+      out = capture_stderr do
+        @convertible.read_yaml(@base, name)
+      end
+      assert_match(/Invalid permalink/, out)
+      assert_match(/#{File.join(@base, name)}/, out)
+    end
   end
 end