Fix bug #81112: Implement JsonSerializable for SplFixedArray

This returns an array for SplFixedArray JSON encoding, which
is more appropriate than an object with integer string keys.

Closes GH-7117.

NEWS

@@ -12,6 +12,9 @@ PHP                                                                        NEWS
 - phpdbg:
   . Fixed bug #81135 (unknown help topic causes assertion failure). (krakjoe)
 
+- SPL:
+  . Fixed buf #81112 (Special json_encode behavior for SplFixedArray). (Nikita)
+
 10 Jun 2021, PHP 8.1.0alpha1
 
 - Core:

UPGRADING

@@ -163,6 +163,7 @@ PHP 8.1 UPGRADE NOTES
 - SPL:
   . SplFileObject::fputcsv() now accepts a new "eol" argument which allow to
     define a custom eol sequence, the default remains the same and is "\n".
+  . SplFixedArray will now be JSON encoded like an array.
 
 ========================================
 2. New Features

ext/spl/config.m4

@@ -2,3 +2,4 @@ PHP_NEW_EXTENSION(spl, php_spl.c spl_functions.c spl_engine.c spl_iterators.c sp
 PHP_INSTALL_HEADERS([ext/spl], [php_spl.h spl_array.h spl_directory.h spl_engine.h spl_exceptions.h spl_functions.h spl_iterators.h spl_observer.h spl_dllist.h spl_heap.h spl_fixedarray.h])
 PHP_ADD_EXTENSION_DEP(spl, pcre, true)
 PHP_ADD_EXTENSION_DEP(spl, standard, true)
+PHP_ADD_EXTENSION_DEP(spl, json)

ext/spl/php_spl.c

@@ -735,9 +735,14 @@ PHP_RSHUTDOWN_FUNCTION(spl) /* {{{ */
 	return SUCCESS;
 } /* }}} */
 
-/* {{{ spl_module_entry */
+static const zend_module_dep spl_deps[] = {
+	ZEND_MOD_REQUIRED("json")
+	ZEND_MOD_END
+};
+
 zend_module_entry spl_module_entry = {
-	STANDARD_MODULE_HEADER,
+	STANDARD_MODULE_HEADER_EX, NULL,
+	spl_deps,
 	"SPL",
 	ext_functions,
 	PHP_MINIT(spl),
@@ -748,4 +753,3 @@ zend_module_entry spl_module_entry = {
 	PHP_SPL_VERSION,
 	STANDARD_MODULE_PROPERTIES
 };
-/* }}} */

ext/spl/spl_fixedarray.c

@@ -31,6 +31,7 @@
 #include "spl_fixedarray.h"
 #include "spl_exceptions.h"
 #include "spl_iterators.h"
+#include "ext/json/php_json.h"
 
 zend_object_handlers spl_handler_SplFixedArray;
 PHPAPI zend_class_entry *spl_ce_SplFixedArray;
@@ -758,6 +759,18 @@ PHP_METHOD(SplFixedArray, getIterator)
 	zend_create_internal_iterator_zval(return_value, ZEND_THIS);
 }
 
+PHP_METHOD(SplFixedArray, jsonSerialize)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+
+	spl_fixedarray_object *intern = Z_SPLFIXEDARRAY_P(ZEND_THIS);
+	array_init_size(return_value, intern->array.size);
+	for (zend_long i = 0; i < intern->array.size; i++) {
+		zend_hash_next_index_insert_new(Z_ARR_P(return_value), &intern->array.elements[i]);
+		Z_TRY_ADDREF(intern->array.elements[i]);
+	}
+}
+
 static void spl_fixedarray_it_dtor(zend_object_iterator *iter)
 {
 	zval_ptr_dtor(&iter->data);
@@ -838,7 +851,8 @@ zend_object_iterator *spl_fixedarray_get_iterator(zend_class_entry *ce, zval *ob
 
 PHP_MINIT_FUNCTION(spl_fixedarray)
 {
-	spl_ce_SplFixedArray = register_class_SplFixedArray(zend_ce_aggregate, zend_ce_arrayaccess, zend_ce_countable);
+	spl_ce_SplFixedArray = register_class_SplFixedArray(
+		zend_ce_aggregate, zend_ce_arrayaccess, zend_ce_countable, php_json_serializable_ce);
 	spl_ce_SplFixedArray->create_object = spl_fixedarray_new;
 	spl_ce_SplFixedArray->get_iterator = spl_fixedarray_get_iterator;
 	spl_ce_SplFixedArray->ce_flags |= ZEND_ACC_REUSE_GET_ITERATOR;

ext/spl/spl_fixedarray.stub.php

@@ -2,7 +2,7 @@
 
 /** @generate-class-entries */
 
-class SplFixedArray implements IteratorAggregate, ArrayAccess, Countable
+class SplFixedArray implements IteratorAggregate, ArrayAccess, Countable, JsonSerializable
 {
     public function __construct(int $size = 0) {}
 
@@ -49,4 +49,6 @@ class SplFixedArray implements IteratorAggregate, ArrayAccess, Countable
     public function offsetUnset($index) {}
 
     public function getIterator(): Iterator {}
+
+    public function jsonSerialize(): array {}
 }

ext/spl/spl_fixedarray_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: aeac254f38638c19a11f7d79ac2e5c2d40924e58 */
+ * Stub hash: 115b2d974b18287654be925c4fdc2236674423eb */
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_SplFixedArray___construct, 0, 0, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, size, IS_LONG, 0, "0")
@@ -39,6 +39,9 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_SplFixedArray_getIterator, 0, 0, Iterator, 0)
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_SplFixedArray_jsonSerialize, 0, 0, IS_ARRAY, 0)
+ZEND_END_ARG_INFO()
+
 
 ZEND_METHOD(SplFixedArray, __construct);
 ZEND_METHOD(SplFixedArray, __wakeup);
@@ -52,6 +55,7 @@ ZEND_METHOD(SplFixedArray, offsetGet);
 ZEND_METHOD(SplFixedArray, offsetSet);
 ZEND_METHOD(SplFixedArray, offsetUnset);
 ZEND_METHOD(SplFixedArray, getIterator);
+ZEND_METHOD(SplFixedArray, jsonSerialize);
 
 
 static const zend_function_entry class_SplFixedArray_methods[] = {
@@ -67,16 +71,17 @@ static const zend_function_entry class_SplFixedArray_methods[] = {
 	ZEND_ME(SplFixedArray, offsetSet, arginfo_class_SplFixedArray_offsetSet, ZEND_ACC_PUBLIC)
 	ZEND_ME(SplFixedArray, offsetUnset, arginfo_class_SplFixedArray_offsetUnset, ZEND_ACC_PUBLIC)
 	ZEND_ME(SplFixedArray, getIterator, arginfo_class_SplFixedArray_getIterator, ZEND_ACC_PUBLIC)
+	ZEND_ME(SplFixedArray, jsonSerialize, arginfo_class_SplFixedArray_jsonSerialize, ZEND_ACC_PUBLIC)
 	ZEND_FE_END
 };
 
-static zend_class_entry *register_class_SplFixedArray(zend_class_entry *class_entry_IteratorAggregate, zend_class_entry *class_entry_ArrayAccess, zend_class_entry *class_entry_Countable)
+static zend_class_entry *register_class_SplFixedArray(zend_class_entry *class_entry_IteratorAggregate, zend_class_entry *class_entry_ArrayAccess, zend_class_entry *class_entry_Countable, zend_class_entry *class_entry_JsonSerializable)
 {
 	zend_class_entry ce, *class_entry;
 
 	INIT_CLASS_ENTRY(ce, "SplFixedArray", class_SplFixedArray_methods);
 	class_entry = zend_register_internal_class_ex(&ce, NULL);
-	zend_class_implements(class_entry, 3, class_entry_IteratorAggregate, class_entry_ArrayAccess, class_entry_Countable);
+	zend_class_implements(class_entry, 4, class_entry_IteratorAggregate, class_entry_ArrayAccess, class_entry_Countable, class_entry_JsonSerializable);
 
 	return class_entry;
 }

ext/spl/tests/splfixedarray_json_encode.phpt

@@ -0,0 +1,18 @@
+--TEST--
+json_encode() on SplFixedArray
+--FILE--
+<?php
+
+echo json_encode(new SplFixedArray()) . "\n";
+echo json_encode(new SplFixedArray(1)) . "\n";
+
+$a = new SplFixedArray(3);
+$a[0] = 0;
+$a[2] = 2;
+echo json_encode($a) . "\n";
+
+?>
+--EXPECT--
+[]
+[null]
+[0,null,2]