Merge branch 'phplib-558' into v1.6

* phplib-558:
  PHPLIB-558: Don't inherit read preference in Database::command

Author: alcaeus

src/Database.php

@@ -249,10 +249,6 @@ public function aggregate(array $pipeline, array $options = [])
      */
     public function command($command, array $options = [])
     {
-        if (! isset($options['readPreference']) && ! is_in_transaction($options)) {
-            $options['readPreference'] = $this->readPreference;
-        }
-
         if (! isset($options['typeMap'])) {
             $options['typeMap'] = $this->typeMap;
         }

tests/Database/DatabaseFunctionalTest.php

@@ -7,6 +7,7 @@
 use MongoDB\Driver\Cursor;
 use MongoDB\Driver\ReadConcern;
 use MongoDB\Driver\ReadPreference;
+use MongoDB\Driver\Server;
 use MongoDB\Driver\WriteConcern;
 use MongoDB\Exception\InvalidArgumentException;
 use MongoDB\Operation\CreateIndexes;
@@ -100,6 +101,22 @@ public function testCommand()
         $this->assertTrue($commandResult->ismaster);
     }
 
+    public function testCommandDoesNotInheritReadPreference()
+    {
+        if ($this->isReplicaSet()) {
+            $this->markTestSkipped('Test only applies to replica sets');
+        }
+
+        $this->database = new Database($this->manager, $this->getDatabaseName(), ['readPreference' => new ReadPreference(ReadPreference::RP_SECONDARY)]);
+
+        $command = ['ping' => 1];
+
+        $cursor = $this->database->command($command);
+
+        $this->assertInstanceOf(Cursor::class, $cursor);
+        $this->assertTrue($cursor->getServer()->isPrimary());
+    }
+
     public function testCommandAppliesTypeMapToCursor()
     {
         $command = ['isMaster' => 1];

tests/FunctionalTestCase.php

@@ -301,6 +301,11 @@ protected function getServerStorageEngine(ReadPreference $readPreference = null)
         throw new UnexpectedValueException('Could not determine server storage engine');
     }
 
+    protected function isReplicaSet()
+    {
+        return $this->getPrimaryServer()->getType() !== Server::TYPE_RS_PRIMARY;
+    }
+
     protected function isShardedCluster()
     {
         if ($this->getPrimaryServer()->getType() == Server::TYPE_MONGOS) {