Output buffering may truncate image output

[rk]

In some server configurations, output buffering will cause the image content to be truncated by approximately 5 rows of pixels. I confirmed that this happened with both PHP 7.4 and 8.0, using both GD and Imagick drivers.

To verify, I recreated the original issue by using ob_start() on the same line in my local MAMP environment. Output was then truncated, and my browser showed an image corrupt message. Swapping it for the correct ob_end_clean() resolved the issue on both my development and the production machines.

This just ensures that any automatic output buffering is turned off properly.