Add $entity_type parameter to field indexing callbacks

Just adding that #1838850: Solr indexing callback assumes field is added to a node is dependent on this patch.

Nick:

I'm not sure I understand your questions, but I'll attempt to answer them anyways.

Apachesolr itself is completely generic in terms of the entities that it handles, at least insofar as these functions are concerned. If you check the patch, you will see that the extra parameter isn't even used by any of the field indexing callbacks that apachesolr includes.

The problem is when you deal with field like Geofield which need to fetch 'more' info for indexing purposes, and they use functions like field_info_instance() which require an entity type and bundle passed as arguments. In Geofield's case, they used 'node' as the entity type and looked for $node->type as the bundle.

Once they are able to get the entity type, then between the entity type, entity id, the bundle can be fetched with entity_extract_ids.

I believe this is the exact conversation we had on IRC prior to you posting #4.

A quick test, if you would like to confim, is to just toss this into a PHP file and execute:

$test1 = 'Hello';
$test2 = 'World';

print test_function($test1, $test2);

function test_function($test1) {
  print $test1;
}

This will just print 'Hello', and won't throw any warnings, notices etc.

Also, this is why PHP provides functions like http://php.net/manual/en/function.func-get-args.php, as we may not always know what arguments are being passed to a function. If you search the drupal codebase for function_get_args(), you will see that there are actually a bunch of use cases where a function is called with arguments passed, despite none being defined in the function signature, and func_get_args() is used to fetch them.