Module-Theme: TopMenu invalid type of value returned

[Krielkip]

#22849 # Preconditions (*)

1. master 2.3-dev

Steps to reproduce (*)

1. Code Review, because of error in our stage.

Expected result (*)

1. Continue with code

Actual result (*)

1. PHP Error

2019/08/23 06:55:05 [error] 13943#13943: *579 FastCGI sent in stderr: "PHP message: PHP Fatal error:  Uncaught TypeError: Argument 4 passed to Magento\Theme\Block\Html\Topmenu::_getHtml() must be of the type array, null given, called in vendor/magento/module-theme/Block/Html/Topmenu.php on line 186 and defined in vendor/magento/module-theme/Block/Html/Topmenu.php:204
Stack trace:
#0 vendor/magento/module-theme/Block/Html/Topmenu.php(186): Magento\Theme\Block\Html\Topmenu->_getHtml(Object(Magento\Framework\Data\Tree\Node), 'submenu', 6, NULL)
#1 vendor/magento/module-theme/Block/Html/Topmenu.php(258): Magento\Theme\Block\Html\Topmenu->_addSubMenu(Object(Magento\Framework\Data\Tree\Node), 0, 'submenu', 6)
#2 vendor/magento/module-theme/Bl" while reading response header from upstream, client: 172.28.128.1, server: *.hypernode.local, request: "GET / HTTP/2.0", upstream: "fastcgi://127.0.0.1:9000", host: "magento2.hypernode.local"

Also added an fix pull request; Which will be linked to this issue.

The issue is that in the topmenu building a submenu, it goes to an function which builds an array of _columnBrake.
Only if $total <= $limit then the return is void; aka null. The _getHtml needs an Array, but gets Null; This results in fatal error.

[m2-assistant]

Hi @Krielkip. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• Summary of the issue
• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.3-develop instance - upcoming 2.3.x release

For more details, please, review the Magento Contributor Assistant documentation.

@Krielkip do you confirm that you were able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

---

• Join Magento Community Engineering Slack and ask your questions in #github channel.

[magento-engcom-team]

Hi @Krielkip. Thank you for your report.
The issue has been fixed in #24252 by @Krielkip in 2.3-develop branch
Related commit(s):

• 60ea2be0db939d8b02f05a31fa833149097f0177
• e9dd493dbd16c0e432ab854ca5af69466a301777

The fix will be available with the upcoming 2.3.4 release.