[php-src] Issue #7988: array_merge a key digit [1-9+] returning 0

Issue: https://github.com/php/php-src/issues/7988 Comment Author: iluuu1994 While admittedly confusing (as integers and strings aren't handled in the same way), it's not a bug. https://www.php.net/manual/en/function.array-merge.php > If the input arrays have the same string keys, then the later value for that key will overwrite > the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite > the original value, but will be appended. To preserve numeric keys, you can use +. ```php var_dump(array_merge([1 => 'foo'], [2 => 'foo'])); // array(2) { // [0]=> // string(3) "foo" // [1]=> // string(3) "foo" // } var_dump([1 => 'foo'] + [2 => 'foo']); // array(2) { // [1]=> // string(3) "foo" // [2]=> // string(3) "foo" // } ```