Fix refcounting on zend_empty_array in ext-uri

NEWS

@@ -55,6 +55,7 @@ PHP                                                                        NEWS
   . Add new Uri\UriError exception that is thrown for internal error
     conditions. (timwolla)
   . Further clean up the internal API. (timwolla)
+  . Fixed bug GH-19892 (Refcounting on zend_empty_array). (ilutov, timwolla)
 
 - Windows:
   . Fix GH-19722 (_get_osfhandle asserts in debug mode when given a socket).

Zend/zend_API.h

@@ -1364,6 +1364,7 @@ ZEND_API zend_result zend_try_assign_typed_ref_zval_ex(zend_reference *ref, zval
 
 #define ZEND_TRY_ASSIGN_REF_ARR(zv, arr) do { \
 	ZEND_ASSERT(Z_ISREF_P(zv)); \
+	ZEND_ASSERT(!(GC_FLAGS(arr) & GC_IMMUTABLE)); \
 	_ZEND_TRY_ASSIGN_ARR(zv, arr, 1); \
 } while (0)
 

ext/uri/php_uri.c

@@ -308,7 +308,7 @@ static zend_result pass_errors_by_ref_and_free(zval *errors_zv, zval *errors)
 		return SUCCESS;
 	}
 
-	ZEND_TRY_ASSIGN_REF_ARR(errors_zv, Z_ARRVAL_P(errors));
+	ZEND_TRY_ASSIGN_REF_TMP(errors_zv, errors);
 	if (EG(exception)) {
 		return FAILURE;
 	}

ext/uri/tests/gh19892.phpt

@@ -0,0 +1,12 @@
+--TEST--
+GH-19892: Successful \Uri\WhatWg\Url::parse() with empty errors array
+--FILE--
+<?php
+
+\Uri\WhatWg\Url::parse('https://example.com', errors: $errors);
+var_dump($errors);
+
+?>
+--EXPECT--
+array(0) {
+}