Convert archiver.inc to PSR-0

The classloader can't find the PEAR Archive class. I'm not sure how that works though, so I wasn't able to dig much further than that. I tried to manually manually run the test case that was failing. This is the PHP error that I got:

"PHP Fatal error: Class 'PEAR\\Archive_Tar\\Archive_Tar' not found in /Users/cweagans/Sites/d8.dev/core/lib/Drupal/Component/Archiver/Tar.php on line 28, referer: http://d8.dev/admin/reports/updates/install"

#5: archiver-psr0-5.patch queued for re-testing.

The Archive_Tar class is 3rd party code, not Drupal code. Also, it is not PSR-0, because it's not PHP 5.3. So...

I'm thinking that file should get moved to /core/vendor/PEAR/Archive_Tar.php, and referenced as a Prefix with the class loader, not as a namespace.

That sounds right, the Symfony autoloader supports PEAR classes, so we can still use it, just not the same as everything else.

Minor nit:

+++ b/core/lib/Drupal/Component/Archiver/Tar.php
@@ -0,0 +1,90 @@
+  public function extract($path, Array $files = array()) {

array is a base datatype, so should be lower-cased, I think. There was some issue about it somewhere... :-)

Also, it's awesome to see that this code can end up in Component. However, Components are not supposed to have any external dependencies. This code has a dependency on the PEAR Archive_Tar class. :-( Not sure what we want to do there, as I'd hate to move it to Drupal\Core but...

Components can depend on other components, right? So why not on a 3rd party component?

Anyway, here is a quick re-roll with the Array fixed and also fixed conflicts in system.info.

Yeah I agree with Berdir, the idea of a Component is it's something that could be used independently of core, so having dependencies isn't the issue, it's having dependencies on application-level Drupal code that would be.

OK, if we include a README.txt file in the Component/Archiver directory stating the dependency with a link to where to get the file, that's good enough for me.

The current Component readme file says that there can be no external dependencies other than other Components, but I'm willing to be a little bit flexible with that on things like this.

I had a feeling that system.tar.inc might be forked, and it is: #486558: Add Archive Tar to Drupal.

So if it's forked, can we legitimately put it in a PEAR directory? Seems more like it should go in Drupal\Component with the rest of the code (and we could possibly look to see if the updated version might be possible un-forkable again).

I hadn't realized that it was forked. Given that, yes, just put it in the Component and document that it's forked. If we are able to convert it to the unforked version later, that can go back in the PEAR directory.

I think that was the only issue, so going out on a limb...

Seconded.

I agree with our view on dependencies. Sounds like everyone is on board, including catch. Reviewed the patch and committed it to 8.x. Thanks all!