5.0.0-rc1 - Uncaught Error: Call to a member function get() on null in db_export.php

[AndNovAtor]

Describe the bug

Unable export a database table from multiple table search from database "view", by "With selected" select box - get 500 server error (PHP Exception)

To Reproduce

Steps to reproduce the behavior:

1. Login to PMA
2. Click on any database
3. Select any table (by click on left checkbox)
4. Click "With selected" select box
5. Choose "Export" on the select box (by click)
6. See error

Expected behavior

Show database table export "view" (as with PMA 4.9)

Screenshots

Server configuration

• Operating system: CentOS 7 (OpenVZ container)
• Web server: nginx 1.16.1 + php-fpm 7.3
• Database version: 5.5.64-MariaDB
• PHP version: 7.3.12
• phpMyAdmin version: 5.0.0-rc1

Client configuration

• Browser: Google Chrome 79.0.3945.88, Mozilla Firefox 71.0
• Operating system: Windows 10 x64

Additional context

(I have PMA 4.9.0.1 on the same server, export tables with "With selected" select box works as expected.)

PHP Exception:

PHP Fatal error:  Uncaught Error: Call to a member function get() on null in /var/www/html/pma5/db_export.php:27
Stack trace:
#0 /var/www/html/pma5/libraries/mult_submits.inc.php(96): include()
#1 /var/www/html/pma5/libraries/classes/Controllers/Database/StructureController.php(326): include('/var/www/html/p...')
#2 /var/www/html/pma5/libraries/classes/Controllers/Database/StructureController.php(130): PhpMyAdmin\Controllers\Database\StructureController->multiSubmitAction()
#3 /var/www/html/pma5/db_structure.php(56): PhpMyAdmin\Controllers\Database\StructureController->index(Array)
#4 {main}
  thrown in /var/www/html/pma5/db_export.php on line 27

Post request:

POST /pma5/db_structure.php HTTP/1.1
Host: ******
Connection: keep-alive
Content-Length: 203
Accept: */*
Origin: https://******
X-Requested-With: XMLHttpRequest
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: cors
Accept-Encoding: gzip, deflate, br
Accept-Language: ru-RU,ru;q=0.9,en-US;q=0.8,en;q=0.7
Cookie: pma_lang_https=ru; phpMyAdmin_https=*****; pmaUser-1_https=******; pmaAuth-1_https=******
ajax_request: true
ajax_page_request: true
db: z******
token: *******
selected_tbl[]: a*******s
submit_mult: export
_nocache: *******
token: *******

(Did I maybe make some PMA wrong settings?...)

[williamdes]

Thank you for the report @AndNovAtor !