From a5545d5badfa204acdb8a76a409bd352ca42092f Mon Sep 17 00:00:00 2001
From: akira yamada <akira@arika.org>
Date: Sat, 14 Dec 2013 22:30:22 +0900
Subject: [PATCH 1/3] post_url tag raises ArgumentError for invalid name

Using post_url tag with invalid name raises TypeError.

It should raise ArgumentError and should display detail of the error to
fix the error.
---
 lib/jekyll/tags/post_url.rb | 11 ++++++++++-
 test/test_tags.rb           | 16 ++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/lib/jekyll/tags/post_url.rb b/lib/jekyll/tags/post_url.rb
index 063e22a4..3076b75e 100644
--- a/lib/jekyll/tags/post_url.rb
+++ b/lib/jekyll/tags/post_url.rb
@@ -7,6 +7,7 @@ module Jekyll
 
       def initialize(name)
         all, path, date, slug = *name.sub(/^\//, "").match(MATCHER)
+        raise ArgumentError unless all
         @slug = path ? path + slug : slug
         @date = Time.parse(date)
       end
@@ -38,7 +39,15 @@ module Jekyll
       def initialize(tag_name, post, tokens)
         super
         @orig_post = post.strip
-        @post = PostComparer.new(@orig_post)
+        begin
+          @post = PostComparer.new(@orig_post)
+        rescue
+          raise ArgumentError.new <<-eos
+Could not parse name of post "#{@orig_post}" in tag 'post_url'.
+
+Make sure the post exists and the name is correct.
+eos
+        end
       end
 
       def render(context)
diff --git a/test/test_tags.rb b/test/test_tags.rb
index b21f4931..193ac998 100644
--- a/test/test_tags.rb
+++ b/test/test_tags.rb
@@ -237,6 +237,22 @@ CONTENT
     end
   end
 
+  context "simple page with invalid post name linking" do
+    should "cause an error" do
+      content = <<CONTENT
+---
+title: Invalid post name linking
+---
+
+{% post_url abc2008-11-21-complex %}
+CONTENT
+
+      assert_raise ArgumentError do
+        create_post(content, {'permalink' => 'pretty', 'source' => source_dir, 'destination' => dest_dir, 'read_posts' => true})
+      end
+    end
+  end
+
   context "gist tag" do
     context "simple" do
       setup do

From 9d259fe31562c5fb22a5ae1bbe3a60ad1cbc0743 Mon Sep 17 00:00:00 2001
From: akira yamada <akira@arika.org>
Date: Sun, 15 Dec 2013 17:18:11 +0900
Subject: [PATCH 2/3] added error description for invalid post name

---
 lib/jekyll/tags/post_url.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/jekyll/tags/post_url.rb b/lib/jekyll/tags/post_url.rb
index 3076b75e..52c5c2ed 100644
--- a/lib/jekyll/tags/post_url.rb
+++ b/lib/jekyll/tags/post_url.rb
@@ -7,7 +7,7 @@ module Jekyll
 
       def initialize(name)
         all, path, date, slug = *name.sub(/^\//, "").match(MATCHER)
-        raise ArgumentError unless all
+        raise ArgumentError.new("invalid post name") unless all
         @slug = path ? path + slug : slug
         @date = Time.parse(date)
       end

From ecab2eb473bc5504b417557c88deb2fe91c6cffe Mon Sep 17 00:00:00 2001
From: akira yamada <akira@arika.org>
Date: Tue, 17 Dec 2013 10:57:12 +0900
Subject: [PATCH 3/3] made error description more helpful

---
 lib/jekyll/tags/post_url.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/jekyll/tags/post_url.rb b/lib/jekyll/tags/post_url.rb
index 52c5c2ed..af366702 100644
--- a/lib/jekyll/tags/post_url.rb
+++ b/lib/jekyll/tags/post_url.rb
@@ -7,7 +7,7 @@ module Jekyll
 
       def initialize(name)
         all, path, date, slug = *name.sub(/^\//, "").match(MATCHER)
-        raise ArgumentError.new("invalid post name") unless all
+        raise ArgumentError.new("'#{name}' does not contain valid date and/or title") unless all
         @slug = path ? path + slug : slug
         @date = Time.parse(date)
       end