[wp-trac] [WordPress Trac] #18855: get_attached_file( $post_id ) wrongly(?) returns the uploads directory when $post_id is not a valid attachment

[WordPress Trac]

#18855: get_attached_file( $post_id ) wrongly(?) returns the uploads directory when
$post_id is not a valid attachment
-----------------------------+------------------------------------
 Reporter:  mikeschinkel     |      Owner:
     Type:  defect (bug)     |     Status:  new
 Priority:  normal           |  Milestone:  Awaiting Review
Component:  Post Thumbnails  |    Version:  3.2.1
 Severity:  normal           |   Keywords:  has-patch dev-feedback
-----------------------------+------------------------------------
 The function `get_attached_file( $post_id )` wrongly(?) returns the
 uploads directory when `$post_id` is not a valid attachment. For example,
 if I run the following code:

 {{{
 $attached_file = get_attached_file(0);
 }}}

 It might return the following on my machine:
 {{{
 /Users/mikeschinkel/Sites/mysite/public_html/wp-content/uploads/
 }}}

 I would instead expect it to simply return `false` indicating that no
 attached file was found:
 {{{
 false
 }}}

 Here is the code I wrote that caused me to recognize the problem:

 {{{
 function has_valid_file_attached( $attachment_id ) {
   return file_exists( get_attached_file( $attachment_id, true ) ) );
 }
 }}}

 Here's the hack I had to write instead:

 {{{

 function has_valid_file_attached( $attachment_id ) {
   $attached_file = get_attached_file( $attachment_id, true );
   if ( '/' == substr( $attached_file, -1, 1 ) )
     return false;

   if ( ! file_exists( $attached_file ) )
     return false;

   return true;
 }
 }}}

 I have attached a patch that simply returns `false` when the value
 returned by the internal call to `get_post_meta( $attachment_id,
 '_wp_attached_file', true )` is an empty string.  I would be surprised to
 find it many people (anyone?) used this function for it's side-effect to
 return the root upload path so I doubt using this path would break
 anything.

 It's not a critical patch because there is an easy workaround, but it cost
 me extra time to figure out why my `has_valid_file_attached()` function
 wasn't reporting `false` when the attachment was missing, so it would be
 nice to keep someone else from having to waste the same time in the
 future.

-- 
Ticket URL: <http://core.trac.wordpress.org/ticket/18855>
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