CDN module rewrites already rewritten protocol-relative URLs [#1466102]

If my CDN server URL is //cdn.example.com/ when using image fields the image URL becomes //cdn.example.com//cdn.example.com/sites/default/files/my-image.png because image field generates the URL to the image which is fed through cdn_file_url_alter(), later the output html is fed through cdn_html_alter_image_urls() which also failed to take into account protocol relative URLs.

The first problem really lies in Drupal core's file_uri_scheme() as it doesn't understand protocol relative URLs, but I don't have the energy to have that fight atm. Instead I decided to add an extra condition to the protocol check in CDN to catch it.

The second problem is caused by the page wide image replacement which checks for base_path() as one of the patterns, so // matches when drupal is installed in the docroot (common use case for people wanting to use a CDN).

Patch coming right up.

Comment	File	Size	Author
#6	1466102-follow_up-6.patch	1.25 KB	Wim Leers
#1	cdn-1466102-protocol-relative-1.patch	1.63 KB	skwashd

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Comments

Comment #1

skwashd CreditAttribution: skwashd commented 3 March 2012 at 10:10

Status:

Active

» Needs review

File	Size
cdn-1466102-protocol-relative-1.patch	1.63 KB

And here it is...

Comment #2

Wim Leers

Ghent 🇧🇪🇪🇺

CreditAttribution: Wim Leers commented 4 March 2012 at 09:28

Title:	CDN breaks URLs when using protocol relative URLs for CDN servers.	» CDN module rewrites already rewritten protocol-relative URLs
Status:	Needs review	» Fixed

Excellent find and excellent patch. I wish there were more contributors like you! :) I only added some docs and backported it to D6. Both commits attributed to you.

D7: http://drupalcode.org/project/cdn.git/commit/033dd53
D6: http://drupalcode.org/project/cdn.git/commit/5d42d04

Comment #3

Wim Leers

Ghent 🇧🇪🇪🇺

CreditAttribution: Wim Leers commented 4 March 2012 at 10:44

Note that when you use ImageCache on D6, it breaks protocol-relative URLs:

  drupal_alter('file_url', $altered_path);

  // If any module has altered the path, then return the alteration...
  if ($altered_path != $old_path) {
    // ...but use url() so our $bypass_browser_cache parameter is honored.
    return url($altered_path, $args);
  }

The url() function in D6 does not honor protocol-relative URLs…

Comment #4

18 March 2012 at 10:50

Status:

Fixed

» Closed (fixed)

Automatically closed -- issue fixed for 2 weeks with no activity.

Comment #5

Wim Leers

Ghent 🇧🇪🇪🇺

CreditAttribution: Wim Leers commented 17 April 2012 at 12:49

Status:

Closed (fixed)

» Active

The committed patch contains a major bug.

preg_quote() is applied to all three items of the array. Unfortunately, you've added regexp syntax to one of the entries, which preg_quote() subsequently escapes… So this actually completely breaks the protocol-relative URL case!

Patch posted as part of the patch at #1535252-3: Support rewriting file URLs in blocks.