Critical Error on getSwatchAttributseData() preventing listing of products in category

[tigerx7]

I'm not sure exactly if the root of the problem is with an issue on a swatch attribute or that the category only has one product, but nonetheless, it causes $result to never be assigned in the following class:

\Magento\Swatches\Block\Product\Renderer\Listing on function getSwatchAttributesData():

    protected function getSwatchAttributesData()
    {
        $swatchAttributeData = parent::getSwatchAttributesData();
        foreach ($swatchAttributeData as $attributeId => $item) {
            if (!empty($item['used_in_product_listing'])) {
                $result[$attributeId] = $item;
            }
        }
        return $result;
    }

The end result is that in production, the category is displayed, but there's no products listed.

I ended up overriding the class on my end and applied $result = []; prior to the foreach loop which seemed to have fixed it. I'm not sure if it'll cause issues anywhere else though.

[yaronish]

@tigerx7 thank you for issue reporting. Internal ticket MAGETWO-47959.

[yaronish]

Fixed