GH-27 fix for incorrect key references for inner joins using has_many_thru with explicit keys

lib/php-activerecord/lib/Relationship.php

···
 			$this->foreign_key = is_array($this->options['foreign_key']) ? $this->options['foreign_key'] : array($this->options['foreign_key']);
 	}
 
+	protected function get_table()
+	{
+		return Table::load($this->class_name);
+	}
+
 	/**
 	 * What is this relationship's cardinality?
 	 *
···
 			$join_table = $from_table;
 			$join_table_name = $from_table->get_fully_qualified_table_name();
 			$from_table_name = Table::load($this->class_name)->get_fully_qualified_table_name();
-
-		}
+ 		}
 		else
 		{
 			$join_table = Table::load($this->class_name);
···
 			$this->set_keys($from_table->class->getName());
 
 			if ($using_through)
+			{
+				$foreign_key = $this->primary_key[0];
 				$join_primary_key = $this->keyify($this->class_name);
+			}
 			else
+			{
 				$join_primary_key = $this->foreign_key[0];
-
-			$foreign_key = $this->primary_key[0];
+				$foreign_key = $this->primary_key[0];
+			}
 		}
 		else
 		{
···
 			$this->set_inferred_class_name();
 	}
 
-	private function get_table()
-	{
-		return Table::load($this->class_name);
-	}
-
-	protected function set_keys($model_class_name)
+	protected function set_keys($model_class_name, $override=false)
 	{
 		//infer from class_name
-		if (!$this->foreign_key)
+		if (!$this->foreign_key || $override)
 			$this->foreign_key = array($this->keyify($model_class_name));
 
-		if (!$this->primary_key)
+		if (!$this->primary_key || $override)
 			$this->primary_key = Table::load($model_class_name)->pk;
 	}
 
 	public function load(Model $model)
 	{
 		$class_name = $this->class_name;
-		$this->set_keys(get_class($model));
 
 		// since through relationships depend on other relationships we can't do
 		// this initiailization in the constructor since the other relationship
···
 				if (!($through_relationship instanceof HasMany) && !($through_relationship instanceof BelongsTo))
 					throw new HasManyThroughAssociationException('has_many through can only use a belongs_to or has_many association');
 
-				$through_table = Table::load(classify($this->through, true));
-				$through_table_name = $through_table->get_fully_qualified_table_name();
+				$this->set_keys($this->get_table()->class->getName());
 
+				$through_table = Table::load(classify($this->through, true));
 				$this->options['joins'] = $this->construct_inner_join_sql($through_table, true);
-				$conn = $this->get_table()->conn;
-
-				foreach ($this->foreign_key as $index => &$key)
-				{
-					$k = $key;
-					$key = "$through_table_name." . $conn->quote_name($k);
-				}
 			}
 
 			$this->initialized = true;
 		}
 
+		$this->set_keys(get_class($model), true);
+
 		if (!($conditions = $this->create_conditions_from_keys($model, $this->foreign_key, $this->primary_key)))
 			return null;
+
 		$options = $this->unset_non_finder_options($this->options);
 		$options['conditions'] = $conditions;
 		return $class_name::find($this->poly_relationship ? 'all' : 'first',$options);

lib/php-activerecord/test/RelationshipTest.php

···
 		$this->assert_equals(3,$hosts[1]->id);
 	}
 
+	public function test_gh27_has_many_through_with_explicit_keys()
+	{
+		$property = Property::first();
+
+		$this->assert_equals(1, $property->amenities[0]->amenity_id);
+		$this->assert_equals(2, $property->amenities[1]->amenity_id);
+	}
+
 	public function test_gh16_has_many_through_inside_a_loop_should_not_cause_an_exception()
 	{
 		$count = 0;

lib/php-activerecord/test/fixtures/amenities.csv

···
+amenity_id, type
+1, "Test #1"
+2, "Test #2"
+3, "Test #3"

lib/php-activerecord/test/fixtures/property_amenities.csv

···
+id, amenity_id, property_id
+257117, 1, 28840
+257118, 2, 28840
+257119, 2, 28841
+257120, 3, 28841

lib/php-activerecord/test/models/Amenity.php

···
+<?php
+class Amenity extends ActiveRecord\Model
+{
+	static $table_name = 'amenities';
+	static $primary_key = 'amenity_id';
+
+	static $has_many = array(
+		array('property_amenities')
+	);
+};
+?>

lib/php-activerecord/test/models/Property.php

···
+<?php
+class Property extends ActiveRecord\Model
+{
+	static $table_name = 'property';
+	static $primary_key = 'property_id';
+
+	static $has_many = array(
+		array('property_amenities'),
+		array('amenities', 'through' => 'property_amenities')
+	);
+};
+?>

lib/php-activerecord/test/models/PropertyAmenity.php

···
+<?php
+class PropertyAmenity extends ActiveRecord\Model
+{
+	static $table_name = 'property_amenities';
+	static $primary_key = 'id';
+
+	static $belongs_to = array(
+		array('amenity'),
+		array('property')
+	);
+};
+?>

lib/php-activerecord/test/sql/mysql.sql

···
 	author_id int,
 	is_awesome int default 1
 );
+
+CREATE TABLE amenities(
+  `amenity_id` int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  `type` varchar(40) NOT NULL DEFAULT ''
+);
+
+CREATE TABLE property(
+  `property_id` int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY
+);
+
+CREATE TABLE property_amenities(
+  `id` int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  `amenity_id` int(11) NOT NULL DEFAULT '0',
+  `property_id` int(11) NOT NULL DEFAULT '0'
+);

lib/php-activerecord/test/sql/sqlite.sql

···
 	author_id int,
 	is_awesome int default 1
 );
+
+CREATE TABLE amenities(
+  `amenity_id` INTEGER NOT NULL PRIMARY KEY,
+  `type` varchar(40) DEFAULT NULL
+);
+
+CREATE TABLE property(
+  `property_id` INTEGER NOT NULL PRIMARY KEY
+);
+
+CREATE TABLE property_amenities(
+  `id` INTEGER NOT NULL PRIMARY KEY,
+  `amenity_id` INT NOT NULL,
+  `property_id` INT NOT NULL
+);