PHPC-1700: Fix memory leak when read preference is invalid (#1179)

* PHPC-1700: Fix memory leak in prep_tagsets

* PHPC-1701: Add regression test for memory leak in prep_authmechanisms

Author: alcaeus

src/MongoDB/ReadPreference.c

@@ -63,9 +63,14 @@ static bool php_phongo_readpreference_init_from_hash(php_phongo_readpreference_t
 	}
 
 	if ((tagSets = zend_hash_str_find(props, "tags", sizeof("tags") - 1))) {
+		ZVAL_DEREF(tagSets);
 		if (Z_TYPE_P(tagSets) == IS_ARRAY) {
 			bson_t* tags = bson_new();
 
+			/* Separate tagSets as php_phongo_read_preference_prep_tagsets may
+			 * modify these tags. */
+			SEPARATE_ZVAL_NOREF(tagSets);
+
 			php_phongo_read_preference_prep_tagsets(tagSets);
 			php_phongo_zval_to_bson(tagSets, PHONGO_BSON_NONE, (bson_t*) tags, NULL);
 

tests/manager/bug1701-001.phpt

@@ -0,0 +1,23 @@
+--TEST--
+PHPC-1701: prep_authmechanismproperties may leak if Manager ctor errors
+--FILE--
+<?php
+
+require_once __DIR__ . "/../utils/basic.inc";
+
+echo throws(function () {
+    // Using a stream context without SSL options causes an exception in the constructor, triggering the potential leak
+    new MongoDB\Driver\Manager(
+            null,
+            ['username' => 'username', 'authMechanism' => 'GSSAPI', 'authMechanismProperties' => ['canonicalize_host_name' => true]],
+            ['context' => stream_context_create([])]
+        );
+}, "MongoDB\Driver\Exception\InvalidArgumentException"), "\n";
+
+?>
+===DONE===
+<?php exit(0); ?>
+--EXPECT--
+OK: Got MongoDB\Driver\Exception\InvalidArgumentException
+Stream-Context resource does not contain "ssl" options array
+===DONE===

tests/readPreference/bug1698-001.phpt

@@ -39,7 +39,7 @@ array(2) {
   ["tags"]=>
   array(1) {
     [0]=>
-    object(stdClass)#%d (1) {
+    array(1) {
       ["dc"]=>
       string(2) "ny"
     }