Bug #77678 [Com]: 7.2.15 Empty array key recognized as string

Edit report at https://bugs.php.net/bug.php?id=77678&edit=1 ID: 77678 Comment by: dantaeusb at live dot com Reported by: dantaeusb at live dot com Summary: 7.2.15 Empty array key recognized as string Status: Feedback Type: Bug Package: Arrays related Operating System: RHEL, Ubuntu PHP Version: 7.2.15 Block user comment: N Private report: N New Comment: Yes, seems like it's happening only if XDebug enabled! Even if the extension is only loaded and not enabled, I can see the error. It's not happening when I disable zend_extension=xdebug.so in config. Previous Comments: ------------------------------------------------------------------------ [2019-02-28 10:18:26] nikic@php.net Can you please check whether this issue goes away if you remove the xdebug and opcache extensions? ------------------------------------------------------------------------ [2019-02-28 09:28:26] dantaeusb at live dot com Description: ------------ Under some circumstances, the following code (shortened, see link below for more info): $selects = array(); foreach (array_keys($this->getAttributesByTable()) as $table) { echo gettype($selects); var_dump($selects); echo gettype($selects[$eavType]); $selects[$eavType][] = $this->_addLoadAttributesSelectFields($select, $table, $eavType); } Got executed with the following result: array .../Abstract.php:992: array (size=0) empty string ( ! ) Fatal error: Uncaught Error: [] operator not supported for strings in .../Abstract.php on line 995 As you can see, it seems like for some reason type of value in an empty array got recognized like a string. I checked a lot of options and asked for community help but as far nobody could answer why is that happening, so I decided to make a bug report. Unfortunately, this happens very rarely under some unknown circumstances, so I can't make test script or make a gdb backtrace using CLI. If you can help me and explain how to grab some more useful data about scope or execution environment Here's the extended discussion with more info: https://stackoverflow.com/questions/54913287/under-some-circumstances-operator-not-supported-for-strings-error-occurs-whe Reproduced on both local (7.2.15, Ubuntu 16.04 x64), dev and production (7.2.15 RHEL 6) environments. Don't think It's related to environment or some modules, but here's the list of installed modules (tried to pick only additionally installed modules). [PHP Modules] ... gd ... iconv igbinary imagick ... mbstring mcrypt mysqli mysqlnd openssl pcntl pcre PDO pdo_mysql Phar posix readline redis Reflection session shmop SimpleXML sockets sodium SPL ... xdebug xml ... Zend OPcache zip zlib [Zend Modules] Xdebug Zend OPcache Excuse me for possible grammar errors and thanks in advance. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=77678&edit=1