PHPC-924: Avoid unnecessary BSON conversion in Cursor::setTypeMap()

src/MongoDB/Cursor.c

@@ -212,6 +212,7 @@ PHP_METHOD(Cursor, setTypeMap)
 	php_phongo_cursor_t *intern;
 	php_phongo_bson_state     state = PHONGO_BSON_STATE_INITIALIZER;
 	zval                     *typemap = NULL;
+	bool                      restore_current_element = false;
 	SUPPRESS_UNUSED_WARNING(return_value) SUPPRESS_UNUSED_WARNING(return_value_ptr) SUPPRESS_UNUSED_WARNING(return_value_used)
 
 
@@ -225,6 +226,7 @@ PHP_METHOD(Cursor, setTypeMap)
 	 * visitor_data, which contains the only reference to it. */
 	if (!Z_ISUNDEF(intern->visitor_data.zchild)) {
 		php_phongo_cursor_free_current(intern);
+		restore_current_element = true;
 	}
 
 	phongo_bson_typemap_to_state(typemap, &state.map TSRMLS_CC);
@@ -233,7 +235,7 @@ PHP_METHOD(Cursor, setTypeMap)
 
 	/* If the cursor has a current element, we just freed it and should restore
 	 * it with a new type map applied. */
-	if (mongoc_cursor_current(intern->cursor)) {
+	if (restore_current_element && mongoc_cursor_current(intern->cursor)) {
 		const bson_t *doc = mongoc_cursor_current(intern->cursor);
 
 		phongo_bson_to_zval_ex(bson_get_data(doc), doc->len, &intern->visitor_data);

tests/cursor/bug0924-001.phpt

@@ -0,0 +1,64 @@
+--TEST--
+PHPC-924: Cursor::setTypeMap() may unnecessarily convert first BSON document (type map)
+--SKIPIF--
+<?php require __DIR__ . "/../utils/basic-skipif.inc"; CLEANUP(STANDALONE) ?>
+--FILE--
+<?php
+require_once __DIR__ . "/../utils/basic.inc";
+
+class MyDocument implements MongoDB\BSON\Serializable, MongoDB\BSON\Unserializable
+{
+    private $data;
+
+    public function __construct($id)
+    {
+        $this->data['_id'] = $id;
+    }
+
+    public function bsonSerialize()
+    {
+        return (object) $this->data;
+    }
+
+    public function bsonUnserialize(array $data)
+    {
+        printf("%s called for ID: %s\n", __METHOD__, $data['_id']);
+        $this->data = $data;
+    }
+}
+
+$manager = new MongoDB\Driver\Manager(STANDALONE);
+
+$bulk = new MongoDB\Driver\BulkWrite();
+$bulk->insert(new MyDocument('a'));
+$bulk->insert(new MyDocument('b'));
+$manager->executeBulkWrite(NS, $bulk);
+
+$cursor = $manager->executeQuery(NS, new MongoDB\Driver\Query([]));
+$cursor->setTypeMap(['root' => 'MyDocument']);
+
+foreach ($cursor as $i => $document) {
+    var_dump($document);
+}
+
+?>
+===DONE===
+<?php exit(0); ?>
+--EXPECTF--
+MyDocument::bsonUnserialize called for ID: a
+object(MyDocument)#%d (%d) {
+  ["data":"MyDocument":private]=>
+  array(1) {
+    ["_id"]=>
+    string(1) "a"
+  }
+}
+MyDocument::bsonUnserialize called for ID: b
+object(MyDocument)#%d (%d) {
+  ["data":"MyDocument":private]=>
+  array(1) {
+    ["_id"]=>
+    string(1) "b"
+  }
+}
+===DONE===

tests/cursor/bug0924-002.phpt

@@ -0,0 +1,80 @@
+--TEST--
+PHPC-924: Cursor::setTypeMap() may unnecessarily convert first BSON document (__pclass)
+--SKIPIF--
+<?php require __DIR__ . "/../utils/basic-skipif.inc"; CLEANUP(STANDALONE) ?>
+--FILE--
+<?php
+require_once __DIR__ . "/../utils/basic.inc";
+
+class MyDocument implements MongoDB\BSON\Persistable
+{
+    private $data;
+
+    public function __construct($id)
+    {
+        $this->data['_id'] = $id;
+    }
+
+    public function bsonSerialize()
+    {
+        return (object) $this->data;
+    }
+
+    public function bsonUnserialize(array $data)
+    {
+        printf("%s called for ID: %s\n", __METHOD__, $data['_id']);
+        $this->data = $data;
+    }
+}
+
+$manager = new MongoDB\Driver\Manager(STANDALONE);
+
+$bulk = new MongoDB\Driver\BulkWrite();
+$bulk->insert(new MyDocument('a'));
+$bulk->insert(new MyDocument('b'));
+$manager->executeBulkWrite(NS, $bulk);
+
+$cursor = $manager->executeQuery(NS, new MongoDB\Driver\Query([]));
+/* This type map will have no effect on the query result, since the document
+ * only contains an ID, but it allows us to test for unnecessary conversion. */
+$cursor->setTypeMap(['array' => 'array']);
+
+foreach ($cursor as $i => $document) {
+    var_dump($document);
+}
+
+?>
+===DONE===
+<?php exit(0); ?>
+--EXPECTF--
+MyDocument::bsonUnserialize called for ID: a
+object(MyDocument)#%d (%d) {
+  ["data":"MyDocument":private]=>
+  array(2) {
+    ["_id"]=>
+    string(1) "a"
+    ["__pclass"]=>
+    object(MongoDB\BSON\Binary)#%d (%d) {
+      ["data"]=>
+      string(10) "MyDocument"
+      ["type"]=>
+      int(128)
+    }
+  }
+}
+MyDocument::bsonUnserialize called for ID: b
+object(MyDocument)#%d (%d) {
+  ["data":"MyDocument":private]=>
+  array(2) {
+    ["_id"]=>
+    string(1) "b"
+    ["__pclass"]=>
+    object(MongoDB\BSON\Binary)#%d (%d) {
+      ["data"]=>
+      string(10) "MyDocument"
+      ["type"]=>
+      int(128)
+    }
+  }
+}
+===DONE===