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ext/standard: Fix array_merge() with an empty array argument #1

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GromNaN wants to merge 1 commit into from
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ext/standard: Fix array_merge() with an empty array argument #1

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19 changes: 15 additions & 4 deletions ext/standard/array.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4275,15 +4275,26 @@ static zend_always_inline void php_array_merge_wrapper(INTERNAL_FUNCTION_PARAMET
ret = &args[0];
}
if (ret) {
if (HT_IS_PACKED(Z_ARRVAL_P(ret))) {
if (HT_IS_WITHOUT_HOLES(Z_ARRVAL_P(ret))) {
HashTable *ht = Z_ARRVAL_P(ret);
/* An array that never had an integer key keeps the ZEND_LONG_MIN
* sentinel; appending to it uses index 0. */
zend_long next_free = ht->nNextFreeElement == ZEND_LONG_MIN ? 0 : ht->nNextFreeElement;

/* array_merge() builds a new array: integer keys are renumbered from
* zero, the next free index is reset and the internal pointer is
* rewound to the first element. The argument may be returned as is
* only when it already behaves like the result of that code path. */
if (HT_IS_PACKED(ht)) {
if (HT_IS_WITHOUT_HOLES(ht) &&
ht->nInternalPointer == 0 &&
next_free == (zend_long) ht->nNumOfElements) {
RETURN_COPY(ret);
}
} else {
} else if (next_free == 0 && ht->nInternalPointer == 0) {
bool copy = true;
zend_string *string_key;

ZEND_HASH_MAP_FOREACH_STR_KEY(Z_ARRVAL_P(ret), string_key) {
ZEND_HASH_MAP_FOREACH_STR_KEY(ht, string_key) {
if (!string_key) {
copy = false;
break;
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42 changes: 42 additions & 0 deletions ext/standard/tests/array/array_merge_empty_array_result.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,42 @@
--TEST--
array_merge() with an empty argument returns an array with a fresh next free index and internal pointer
--FILE--
<?php
// array_merge() with an empty argument returns the other argument itself. The
// result must still behave like a fresh array: integer keys renumbered from 0,
// next free index reset and internal pointer on the first element.

$a = [1, 2, 3];
unset($a[2]);
$r = array_merge($a, []);
$r[] = 4;
var_dump($r);

$b = ['a' => 1];
$b[] = 2;
unset($b[0]);
$r = array_merge([], $b);
$r[] = 3;
var_dump($r);

$c = [10, 20, 30];
next($c);
next($c);
var_dump(current(array_merge([], $c)));
?>
--EXPECT--
array(3) {
[0]=>
int(1)
[1]=>
int(2)
[2]=>
int(4)
}
array(2) {
["a"]=>
int(1)
[0]=>
int(3)
}
int(10)
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