Get MainCategory from BaseProductToCategoryLink collection

[micmil]

[Question (in english) - remember to come back and check the answer that solves your question to mark it as resolved, formatting of messages with markdown]

Litium version: [6.3.7]

I’m working on an article import which needs to be modified, and in the part where variants are added to a MainCategory it is fetched like this:
var editableBaseProduct = baseProduct.MakeWritableClone();
mainCategory = editableBaseProduct.CategoryLinks.First(c => c.MainCategory);
Add variants to it:
mainCategory.ActiveVariantSystemIds.Add(variant.SystemId);

It is working fine but then I noticed that on a product with 2 categories, both of them had MainCategory as “true” when i was debugging, that shouldn’t be possible or should it?

If I use the GetMainCategory extension one category is returned. I went on to check in Litium/Plan section and saw that the category that was returned was not selected, the other category was, why is that?

Basically I need to know if I’m adding variants to the correct MainCategory.

[patric.forsgard]

One base product can only have one main category selected in each assortment.

[micmil]

There is only one assortment, the image shows 2 categories that belong to the same assortment as I see it.

If I do: baseProduct.GetMainCategory(CurrentState.Current.WebSiteID); I get the “Glasull” category which is not the selected one as in the image.
When I look in baseProduct.CategoryLinks both categories have MainCategory property as “true”.

I can use the extension for getting the MainCategory but I wanted to know if this is a bug or is this behaviour normal?

[patric.forsgard]

Please, report that as a bug on our docs-site, it sounds like a validation rule is missing.

[micmil]

Ok, thanks for your help!