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Self troubleshooting

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Version

1.9.2

Description

If the config.php file does not set the $yourls_reserved_URL variable, trying to add a shorturl will make YOURLS try in_array( 'newkeyword', NULL) when checking if the keyword is reserved, and the script will crash.

Expectation

YOURLS should handle the case where this variable is not set, and treat it the same as if it is set to an empty array.

Reproduction steps

1. Remove or comment out the definition of $yourls_reserved_URL in config.php
2. Try to shorten a new URL

Context

Exposed via troubleshooting in #3767; documentation workaround suggested in #3768.