Confirmed: Browser blocks sending when not both fields are filled.

Just BTW: I tried to enter 0 for the height to test if it's then resized proportionally depending on the width. I get an absolutely not helpful Joomla error message (alert) "No valid image was loaded." after page has reloaded.

Here is a fun bug for you.. used the 0/90/180/270 buttons on the media rotate page, and the image magically changes dimensions... but when you save it magically jumps back to the original dimensions, but rotated... Just one of many issues with the Javascript based media manager.

@PhilETaylor some of the reported issues should be fixed with #33192

I'll take a look as soon as my back pain allows extended time at a desk. Thanks.

For this issue the main problem seems to be that administrator\components\com_templates\src\Model\TemplateModel.php::resizeImage() uses a hard coded Image::SCALE_FILL. That's a scale method that needs a defined height AND width.

As a model method it should be more flexible.

I think the more popular/more often expected scale methods would be

• Image::SCALE_INSIDE (The larger h or w decides. The other is adjusted. Ratio is retained.). That's the default scale constant of Joomla\CMS\Image\Image::resize().
• maybe sometimes Image::SCALE_OUTSIDE (Care is taken that w or h is not undercut. Ratio is retained.).