fix post.permalink error when config.relative_link is true (#2760)

* fix a bug that post.permalink error when config.relative_link is true

* fix jscs Illegal trailing whitespace

Author: tcatche

lib/models/post.js

@@ -58,6 +58,7 @@ module.exports = function(ctx) {
     var self = _.assign({}, ctx.extend.helper.list(), ctx);
     var config = ctx.config;
     var partial_url = self.url_for(this.path);
+    if (config.relative_link) partial_url = '/' + partial_url;
     return config.url + _.replace(partial_url, config.root, '/');
   });
 

test/scripts/models/post.js

@@ -83,6 +83,18 @@ describe('Post', () => {
     });
   });
 
+  it('permalink - virtual - when set relative_link', () => {
+    hexo.config.root = '/';
+    hexo.config.relative_link = true;
+    return Post.insert({
+      source: 'foo.md',
+      slug: 'bar'
+    }).then(data => {
+      data.permalink.should.eql(hexo.config.url + '/' + data.path);
+      return Post.removeById(data._id);
+    });
+  });
+
   it('permalink_root_prefix - virtual', () => {
     hexo.config.url = 'http://yoursite.com/root';
     hexo.config.root = '/root/';
@@ -95,6 +107,19 @@ describe('Post', () => {
     });
   });
 
+  it('permalink_root_prefix - virtual - when set relative_link', () => {
+    hexo.config.url = 'http://yoursite.com/root';
+    hexo.config.root = '/root/';
+    hexo.config.relative_link = true;
+    return Post.insert({
+      source: 'foo.md',
+      slug: 'bar'
+    }).then(data => {
+      data.permalink.should.eql(hexo.config.url + '/' + data.path);
+      return Post.removeById(data._id);
+    });
+  });
+
   it('full_source - virtual', () => Post.insert({
     source: 'foo.md',
     slug: 'bar'