Divide by zero

[ambroisemaupate]

A divide by zero is occuring in Util.php on line 59 in calculateDependantSizes method.

When ratio is not set or null or 0.

Could we throw an exception when this method parameters does not match requirements?

Moreover $ratio can be zero in ImageConvertAttributesFormatter line 40
$originalRatio = $originalHeight ? $originalWidth/$originalHeight : 0;

[millejano]

There is also a "Division by zero" Warning if using a combination of keep-ration and ignore-error for a non existing image.

An example:
styles.xml
<img class="image" height="7.5cm" width="10cm" ignore-error="true" keep-ratio="keep-ratio" />

image.pdf.twig
<img class="image" src="{{ image.url }}" />

The images doesn't exists.

Warning Message: Division by zero
see psliwa/php-pdf/lib/PHPPdf/Core/Node/Image.php at line 97
$sourceRatio = $sourceImage->getOriginalHeight() / $sourceImage->getOriginalWidth();

Quickfix for line 94
before:
if($keepRatio
after:
if($keepRatio && $sourceImage->getOriginalWidth())

Can you fix this booth issues in a new version, pls.