[Plugin: SI CAPTCHA Anti-Spam] Suggested code improvement

When I run the “Secureimage PHP Requirements Test”, I get:

PHP Version: 5.2.6
System: Linux
GD Support: Yes!
GD Version: bundled (2.0.34 compatible)
TTF Support (FreeType): Yes!
JPEG Support: No
PNG Support: Yes!
GIF Read Support: Yes!
GIF Create Support: Yes!
Since you can see this...
Secureimage Will Work!!

So I left it at that, even though the JPEG Support was at No.

But I now noticed that sometimes, the CAPTCHA image would be blank.
Digging into the plugin code, I found that this happened when a JPEG background was picked for the background directory.
To solve this, here’s the modified code:

function getBackgroundFromDirectory()
...
while (($file = readdir($dh)) !== false) {
  $supported_formats = array();
  $gd_support = extension_loaded('gd');
  if ($gd_support) $gd_info = gd_info(); else $gd_info = array();
  if ($gd_support && $gd_info['JPG Support']) $supported_formats[] = 'jpg';
  if ($gd_support && $gd_info['PNG Support']) $supported_formats[] = 'png';
  if ($gd_support && $gd_info['GIF Create Support']) $supported_formats[] = 'gif';
  if (preg_match('/('.implode('|', $supported_formats).')$/i', $file)) $images[] = $file;
}

That way, only the supported image types will be used for backgrounds.

Thanks for the nice plugin.

Cheers.

https://www.ads-software.com/extend/plugins/si-captcha-for-wordpress/