diff --git a/benchmark/flat-map b/benchmark/flat-map
new file mode 100644
index 00000000..b10c5c9a
--- /dev/null
+++ b/benchmark/flat-map
@@ -0,0 +1,17 @@
+require 'benchmark/ips'
+
+enum = (0..50).to_a
+nested = enum.map { |i| [i] }
+
+def do_thing(blah)
+  blah * 1
+end
+
+Benchmark.ips do |x|
+  x.report('.map.flatten with nested arrays') { nested.map { |i| do_thing(i) }.flatten(1) }
+  x.report('.flat_map with nested arrays')    { nested.flat_map { |i| do_thing(i) } }
+
+  x.report('.map.flatten with no nested arrays') { enum.map { |i| do_thing(i) }.flatten(1) }
+  x.report('.flat_map with no nested arrays')    { enum.flat_map { |i| do_thing(i) } }
+end
+
diff --git a/benchmark/hash-fetch b/benchmark/hash-fetch
new file mode 100644
index 00000000..35708357
--- /dev/null
+++ b/benchmark/hash-fetch
@@ -0,0 +1,9 @@
+require 'benchmark/ips'
+
+h = {:bar => 'uco'}
+
+Benchmark.ips do |x|
+  x.report('fetch with no block') { h.fetch(:bar, (0..9).to_a)    }
+  x.report('fetch with a block')  { h.fetch(:bar) { (0..9).to_a } }
+  x.report('brackets with an ||') { h[:bar] || (0..9).to_a        }
+end
diff --git a/benchmark/proc-call-vs-yield b/benchmark/proc-call-vs-yield
new file mode 100644
index 00000000..3d55979b
--- /dev/null
+++ b/benchmark/proc-call-vs-yield
@@ -0,0 +1,14 @@
+require 'benchmark/ips'
+
+def fast
+  yield
+end
+
+def slow(&block)
+  block.call
+end
+
+Benchmark.ips do |x|
+  x.report('yield') { fast { (0..9).to_a } }
+  x.report('block.call') { slow { (0..9).to_a } }
+end
diff --git a/benchmark/sequential-assignment b/benchmark/sequential-assignment
new file mode 100644
index 00000000..945e982b
--- /dev/null
+++ b/benchmark/sequential-assignment
@@ -0,0 +1,11 @@
+require 'benchmark/ips'
+
+Benchmark.ips do |x|
+  x.report('parallel assignment') do
+    a, b = 1, 2
+  end
+  x.report('multi-line assignment') do
+    a = 1
+    b = 2
+  end
+end
diff --git a/benchmark/string-concat b/benchmark/string-concat
new file mode 100644
index 00000000..c4a91748
--- /dev/null
+++ b/benchmark/string-concat
@@ -0,0 +1,8 @@
+require 'benchmark/ips'
+
+url = "http://jekyllrb.com"
+
+Benchmark.ips do |x|
+  x.report('+=') { url += '/' }
+  x.report('<<') { url << '/' }
+end
diff --git a/benchmark/string-replacement b/benchmark/string-replacement
new file mode 100644
index 00000000..13715376
--- /dev/null
+++ b/benchmark/string-replacement
@@ -0,0 +1,13 @@
+require 'benchmark/ips'
+
+def str
+  'http://baruco.org/2014/some-talk-with-some-amount-of-value'
+end
+
+Benchmark.ips do |x|
+  x.report('#tr')    { str.tr('some', 'a')    }
+  x.report('#gsub')  { str.gsub('some', 'a')  }
+  x.report('#gsub!') { str.gsub!('some', 'a') }
+  x.report('#sub')   { str.sub('some', 'a')  }
+  x.report('#sub!')  { str.sub!('some', 'a') }
+end
diff --git a/benchmark/symbol-to-proc b/benchmark/symbol-to-proc
new file mode 100644
index 00000000..bc08b2f2
--- /dev/null
+++ b/benchmark/symbol-to-proc
@@ -0,0 +1,6 @@
+require 'benchmark/ips'
+
+Benchmark.ips do |x|
+  x.report('block')  { (1..100).map { |i| i.to_s } }
+  x.report('&:to_s') { (1..100).map(&:to_s) }
+end
diff --git a/lib/jekyll/cleaner.rb b/lib/jekyll/cleaner.rb
index 0aa3cdfd..1786a317 100644
--- a/lib/jekyll/cleaner.rb
+++ b/lib/jekyll/cleaner.rb
@@ -76,7 +76,7 @@ module Jekyll
       #
       # Returns a Set with the directory paths
       def keep_dirs
-        site.keep_files.map{|file| parent_dirs(File.join(site.dest, file))}.flatten.to_set
+        site.keep_files.map { |file| parent_dirs(File.join(site.dest, file)) }.flatten.to_set
       end
 
       # Private: Creates a regular expression from the config's keep_files array
diff --git a/lib/jekyll/page.rb b/lib/jekyll/page.rb
index d045b7c2..dcbd3ac5 100644
--- a/lib/jekyll/page.rb
+++ b/lib/jekyll/page.rb
@@ -126,7 +126,7 @@ module Jekyll
     #
     # Returns the path to the source file
     def path
-      data.fetch('path', relative_path.sub(/\A\//, ''))
+      data.fetch('path') { relative_path.sub(/\A\//, '') }
     end
 
     # The path to the page source file, relative to the site source
diff --git a/lib/jekyll/post.rb b/lib/jekyll/post.rb
index 293e2c5d..68b85acb 100644
--- a/lib/jekyll/post.rb
+++ b/lib/jekyll/post.rb
@@ -108,14 +108,14 @@ module Jekyll
     #
     # Returns excerpt string.
     def excerpt
-      data.fetch('excerpt', extracted_excerpt.to_s)
+      data.fetch('excerpt') { extracted_excerpt.to_s }
     end
 
     # Public: the Post title, from the YAML Front-Matter or from the slug
     #
     # Returns the post title
     def title
-      data.fetch("title", titleized_slug)
+      data.fetch('title') { titleized_slug }
     end
 
     # Turns the post slug into a suitable title
@@ -130,7 +130,7 @@ module Jekyll
     #
     # Returns the path to the file relative to the site source
     def path
-      data.fetch('path', relative_path.sub(/\A\//, ''))
+      data.fetch('path') { relative_path.sub(/\A\//, '') }
     end
 
     # The path to the post source file, relative to the site source
diff --git a/lib/jekyll/url.rb b/lib/jekyll/url.rb
index f4ea4d33..777ae3d1 100644
--- a/lib/jekyll/url.rb
+++ b/lib/jekyll/url.rb
@@ -46,24 +46,23 @@ module Jekyll
     # Returns the _unsanitizied_ String URL
     def generate_url
       @placeholders.inject(@template) do |result, token|
+        break result if result.index(':').nil?
         result.gsub(/:#{token.first}/, self.class.escape_path(token.last))
       end
     end
 
     # Returns a sanitized String URL
     def sanitize_url(in_url)
-
-      # Remove all double slashes
-      url = in_url.gsub(/\/\//, "/")
-
-      # Remove every URL segment that consists solely of dots
-      url = url.split('/').reject{ |part| part =~ /^\.+$/ }.join('/')
+      url = in_url \
+        # Remove all double slashes
+        .gsub(/\/\//, '/') \
+        # Remove every URL segment that consists solely of dots
+        .split('/').reject{ |part| part =~ /^\.+$/ }.join('/') \
+        # Always add a leading slash
+        .gsub(/\A([^\/])/, '/\1')
 
       # Append a trailing slash to the URL if the unsanitized URL had one
-      url += "/" if in_url =~ /\/$/
-
-      # Always add a leading slash
-      url.gsub!(/\A([^\/])/, '/\1')
+      url << "/" if in_url[-1].eql?('/')
 
       url
     end
diff --git a/test/test_url.rb b/test/test_url.rb
index 0576eda2..dcbe8bed 100644
--- a/test/test_url.rb
+++ b/test/test_url.rb
@@ -16,6 +16,13 @@ class TestURL < Test::Unit::TestCase
       ).to_s
     end
 
+    should "handle multiple of the same key in the template" do
+      assert_equal '/foo/bar/foo/', URL.new(
+        :template => "/:x/:y/:x/",
+        :placeholders => {:x => "foo", :y => "bar"}
+      ).to_s
+    end
+
     should "return permalink if given" do
       assert_equal "/le/perma/link", URL.new(
         :template => "/:x/:y",