output_buffering check broken in sys information report

[ggppdk]

Wrongly detected when

1. ini_get('output_buffering') === 'On' any non numeric and text value means off (a misconfiguration)
2. ini_get('output_buffering') === '0' wrongly detected because we do

https://github.com/joomla/joomla-cms/blob/staging/administrator/components/com_admin/models/sysinfo.php#L251

'output_buffering' => ($outputBuffering === 'On') ? true : is_numeric($outputBuffering),

aka we use is_numeric($outputBuffering) but is_numeric on '0' returns true

Number 2 is most important, since 1 number is a misconfiguration although it may not be an uncommon misconfiguration

See comment
#19611 (comment)

[ggppdk]

@zero-24 , @Quy

Issue due to PR #19611,
The PR tried to fix real issue #19033 ?
but the fix was not correct

[sandewt]

See also PR #19612.

[zero-24]

But Isn't than 'output_buffering === off also invalid / misconfiguration?

[ggppdk]

But Isn't than 'output_buffering === off also invalid / misconfiguration?

Yes === 'off' is invalid (you are supposed to use php_flag output_buffering off to set a boolean 'off')
just i do not mention it above because it is correctly detected by current code as OFF

If you try to set it to a text value
php_value output_buffering On (and any text value)

• on some servers it will give internal error,
• on some it will be accepted just it results to output buffering being off

php_flag output_buffering on (.htaccess)
output_buffering=on (php.ini, restart apache if needed)

Both of the above will set output_buffering to '1' (output buffering enabled)
var_dump(ini_get('output_buffering'));

Display:
string(1) "1"

Please note also that this will enable output buffering ... despite being negative and having text at its end
(it will enable it if you do not get an internal server error)
php_value output_buffering -4096test

So correct detection is
$isEnabled = (int) ini_get('output_buffering') !== 0;

[ggppdk]

I do not mention it above but it is similar to On case

php_flag output_buffering off (.htaccess)
output_buffering=off (php.ini, restart apache if needed)

Both of the above will set output_buffering to '0' (output buffering disabled)
var_dump(ini_get('output_buffering'));

Display:
string(1) "0"

[zero-24]

PR: #19791 Thanks for the report!

[joomla-cms-bot]

Set to "closed" on behalf of @Quy by The JTracker Application at issues.joomla.org/joomla-cms/19784