Multiple feeds importer on the same entity should not override each other’s hashes

Crosslinking #1539224-63: Add support for unique fields to be unique site wide.

I have not tested the patch, but it seems to create entries in the feeds_item table for each imported or updated entity per importer. This could solve problems with importer ID's and hashes being overwritten when multiple importers update the same entities.

Right now I am swamped with work, but hopefully I will have some time soon to reroll and test your patch with the latest dev release.

I have re-rolled patch from #8 against last dev version and added the update function in feeds.install
Be aware this patch will therefore slightly modify your feeds_item table structure:

/**
 * Add id as a primary key of {feeds_item}.
 */
function feeds_update_7213() {
  db_drop_primary_key('feeds_item');
  db_add_primary_key('feeds_item', array('entity_type', 'entity_id', 'id'));
}

Attached patch in conjunction with patch #69 from #1539224-69: Add support for unique fields to be unique site wide works great for me with Commerce product entities, taxonomy terms and nodes.

1. +++ b/plugins/FeedsProcessor.inc
   @@ -266,7 +266,14 @@ abstract class FeedsProcessor extends FeedsPlugin {
   +        $force_update = $this->config['skip_hash_check'];
            $hash = $this->hash($item);
   +        if ($force_update) {
   +          $feeds_item_info = feeds_item_info_load($this->entityType(), $entity_id, $this->id);
   +          if (is_object($feeds_item_info) && isset($feeds_item_info->hash)) {
   +            $hash = $feeds_item_info->hash;
   +          }
   +        }
   

   This comes from #2305751: Skip hash check should not update hash column in feeds item table and as said there it was not clear why that change is needed for this issue.
   If it is not needed to fix this issue, we should leave it out here.

2. This could use an automated test. The test should do something like the following:
   1. Create two importers that both have the "update existing nodes" option enabled.
   2. With importer 1, import source file 1. This should create a node.
   3. With importer 2, import source file 2. This should update the node created by importer 1.
   4. Import source file 1 again with importer 1. No nodes should be updated because the hash created during the first import should not have been overwritten.
   5. Import source file 2 again with importer 2. Again no nodes should be updated.

I've added an updated patch without the the extra code for skipping hash checks, as pointed out it's a separate issue.

@jrusse27
Great. Do you want to write a test for this issue as well? See #10 for what should be covered by the test.

Patch reapply for beta 4 feeds since patch 9 is passed.

Patch fix for beta 4 allow unique hash for individual feed. patch reroll

This is a problem in D8 version as well.

This has been fixed in the 8.x-3.x version in #3105322: Support multiple values for Feeds item so entities can be updated by multiple feeds, so we can move this back to 7.x-2.x if there is still interest to fix it there.

Test from #10 added.