More safe properties check

demo/assets/index.css

@@ -97,6 +97,9 @@ body {
   -webkit-column-count: 2;
   column-count: 2;
 }
+.footnotes-list {
+  padding-left: 2em;
+}
 .gh-ribbon {
   display: block;
   position: absolute;

demo/assets/index.js

@@ -118,7 +118,7 @@
         // copy config to defaults, but only if key exists
         // and value has the same type
         _.forOwn(opts, function (val, key) {
-          if (!defaults.hasOwnProperty(key)) { return; }
+          if (!_.has(defaults, key)) { return; }
 
           // Legacy, for old links
           if (key === '_src') {

demo/assets/index.styl

@@ -89,6 +89,9 @@ body
   -webkit-column-count 2
   column-count 2
 
+.footnotes-list
+  padding-left 2em
+
 .gh-ribbon
   display block
   position absolute

lib/common/utils.js

@@ -7,6 +7,12 @@ function _class(obj) { return Object.prototype.toString.call(obj); }
 
 function isString(obj) { return _class(obj) === '[object String]'; }
 
+var _hasOwnProperty = Object.prototype.hasOwnProperty;
+
+function has(object, key) {
+  return object ? _hasOwnProperty.call(object, key) : false;
+}
+
 // Merge objects
 //
 function assign(obj /*from1, from2, from3, ...*/) {
@@ -74,7 +80,7 @@ var entities = require('./entities');
 function replaceEntityPattern(match, name) {
   var code = 0;
 
-  if (entities.hasOwnProperty(name)) {
+  if (has(entities, name)) {
     return entities[name];
   } else if (name.charCodeAt(0) === 0x23/* # */ && DIGITAL_ENTITY_TEST_RE.test(name)) {
     code = name[1].toLowerCase() === 'x' ?
@@ -120,6 +126,7 @@ function escapeHtml(str) {
 
 exports.assign            = assign;
 exports.isString          = isString;
+exports.has               = has;
 exports.unescapeMd        = unescapeMd;
 exports.isValidEntityCode = isValidEntityCode;
 exports.fromCodePoint     = fromCodePoint;

lib/renderer.js

@@ -2,6 +2,7 @@
 
 
 var assign          = require('./common/utils').assign;
+var has             = require('./common/utils').has;
 var unescapeMd      = require('./common/utils').unescapeMd;
 var replaceEntities = require('./common/utils').replaceEntities;
 var escapeHtml      = require('./common/utils').escapeHtml;
@@ -73,7 +74,7 @@ rules.fence = function (tokens, idx, options, env, self) {
 
     fenceName = token.params.split(/\s+/g)[0];
 
-    if (self.rules.fence_custom.hasOwnProperty(fenceName)) {
+    if (has(self.rules.fence_custom, fenceName)) {
       return self.rules.fence_custom[fenceName](tokens, idx, options, env, self);
     }
 

lib/rules_inline/entity.js

@@ -3,6 +3,7 @@
 'use strict';
 
 var entities          = require('../common/entities');
+var has               = require('../common/utils').has;
 var isValidEntityCode = require('../common/utils').isValidEntityCode;
 var fromCodePoint     = require('../common/utils').fromCodePoint;
 
@@ -32,7 +33,7 @@ module.exports = function entity(state, silent) {
     } else {
       match = state.src.slice(pos).match(NAMED_RE);
       if (match) {
-        if (entities.hasOwnProperty(match[1])) {
+        if (has(entities, match[1])) {
           if (!silent) { state.pending += entities[match[1]]; }
           state.pos += match[0].length;
           return true;