On my site Im using: mysite.com/blog/%postname%/%post_id%/ as Permalink structure.
So I have 1 post at: mysite.com/blog/my-first-post/1234/
But this same post is also possible to visit at: (without postID) mysite.com/blog/my-first-post/
Will that cause double contents issue? Why or how is it possible to visit this same post with 2 different URLS? I don't understand why WordPress do this. Im using WordPress 3.6.1
What does it show in Wordpress/Site? If all links on your site point to mysite.com/blog/my-first-post/1234 Google will visit that link and not your mysite.com/blog/my-first-post. As far as I know, Google will not be aware of that link.
But if in your post/wordpress you manually link to your post/page as mysite.com/blog/my-first-post then, Google will visit it and maybe mark it as duplicate content.
Even on StackOverflow, the url stackoverflow.com/questions/19253513/wordpress-permalink-structure-mysite-com-blog-postname-post-id will be the same as stackoverflow.com/questions/19253513 , but on every link there is on stackoverflow to that page, the URL will be the former. Google doesn't know about the latter link.
