Uncaught TypeError: Argument 1 passed to PhpMyAdmin\Export::outputHandler() must be of the type string or null, boolean given, ExportJson.php on line 273

[williamdes]

<br />
<font size='1'><table class='xdebug-error xe-uncaught-exception' dir='ltr' border='1' cellspacing='0' cellpadding='1'>
<tr><th align='left' bgcolor='#f57900' colspan="5"><span style='background-color: #cc0000; color: #fce94f; font-size: x-large;'>( ! )</span> Fatal error: Uncaught TypeError: Argument 1 passed to PhpMyAdmin\Export::outputHandler() must be of the type string or null, boolean given, called in /mnt/Dev/phpmyadmintest/libraries/classes/Plugins/Export/ExportJson.php on line 273 and defined in /mnt/Dev/phpmyadmintest/libraries/classes/Export.php on line <i>78</i></th></tr>
<tr><th align='left' bgcolor='#f57900' colspan="5"><span style='background-color: #cc0000; color: #fce94f; font-size: x-large;'>( ! )</span> TypeError: Argument 1 passed to PhpMyAdmin\Export::outputHandler() must be of the type string or null, boolean given, called in /mnt/Dev/phpmyadmintest/libraries/classes/Plugins/Export/ExportJson.php on line 273 in /mnt/Dev/phpmyadmintest/libraries/classes/Export.php on line <i>78</i></th></tr>
<tr><th align='left' bgcolor='#e9b96e' colspan='5'>Call Stack</th></tr>
<tr><th align='center' bgcolor='#eeeeec'>#</th><th align='left' bgcolor='#eeeeec'>Time</th><th align='left' bgcolor='#eeeeec'>Memory</th><th align='left' bgcolor='#eeeeec'>Function</th><th align='left' bgcolor='#eeeeec'>Location</th></tr>
<tr><td bgcolor='#eeeeec' align='center'>1</td><td bgcolor='#eeeeec' align='center'>0.0000</td><td bgcolor='#eeeeec' align='right'>447808</td><td bgcolor='#eeeeec'>{main}(  )</td><td title='/mnt/Dev/phpmyadmintest/export.php' bgcolor='#eeeeec'>.../export.php<b>:</b>0</td></tr>
<tr><td bgcolor='#eeeeec' align='center'>2</td><td bgcolor='#eeeeec' align='center'>0.1279</td><td bgcolor='#eeeeec' align='right'>1994048</td><td bgcolor='#eeeeec'>PhpMyAdmin\Export->exportTable(  )</td><td title='/mnt/Dev/phpmyadmintest/export.php' bgcolor='#eeeeec'>.../export.php<b>:</b>575</td></tr>
<tr><td bgcolor='#eeeeec' align='center'>3</td><td bgcolor='#eeeeec' align='center'>0.1291</td><td bgcolor='#eeeeec' align='right'>1999824</td><td bgcolor='#eeeeec'>PhpMyAdmin\Plugins\Export\ExportJson->exportData(  )</td><td title='/mnt/Dev/phpmyadmintest/libraries/classes/Export.php' bgcolor='#eeeeec'>.../Export.php<b>:</b>990</td></tr>
<tr><td bgcolor='#eeeeec' align='center'>4</td><td bgcolor='#eeeeec' align='center'>0.1295</td><td bgcolor='#eeeeec' align='right'>2021656</td><td bgcolor='#eeeeec'>PhpMyAdmin\Export->outputHandler(  )</td><td title='/mnt/Dev/phpmyadmintest/libraries/classes/Plugins/Export/ExportJson.php' bgcolor='#eeeeec'>.../ExportJson.php<b>:</b>273</td></tr>
</table></font>
</div><div id="selflink" class="print_ignore"><a href="export.php?db=xxx&table=address_mission&server=12&target=&single_table=TRUE" title="Ouvrir une nouvelle fenêtre phpMyAdmin" target="_blank" rel="noopener noreferrer"><img src="themes/dot.gif" title="Ouvrir une nouvelle fenêtre phpMyAdmin" alt="Ouvrir une nouvelle fenêtre phpMyAdmin" class="icon ic_window-new"></a></div><div class="clearfloat" id="pma_errors"></div><script data-cfasync="false" type="text/javascript">// <![CDATA[
var debugSQLInfo = 'null';
AJAX.scriptHandler;
$(function() {});
// ]]></script></body></html>

[sijie123]

Hello! I'm new around here, so do let me know if I missed anything.

I took a look at the exact line pointed out in the error:

if (! $this->export->outputHandler($this->encode($data))) {
    return false;
}

encode($data) calls json_encode, which will return false on failure.
Indeed, this could cause a crash with a TypeError exception if the encode($data) fails and returns false

I would be very happy to submit a fix for this. Please let me know if that's okay - and I'll work on it. Additionally, since this bug seems exist across all of the versions, should I patch this against master or one of the releases?

Finally, I could help write some unit tests to ensure that this is protected against regression, although it would be good if I could get some information from @williamdes on how to reproduce the error.

[williamdes]

@sijie123 You can submit a PR against QA_4_8 and we will add your patch on master

If you want to write Unit tests, open a PR against master.
Thank you for wanting to help us!

I will send you more information in order to reproduce the issue