Fixed Undefined Key error in nested relationship

[kohlerdominik]

Hello there

When using nested, optional relationships (which might be quite an edge case) there is a small possibility that the library is throwing an error.

It is correctly described in the comment above the problematic line, that The first model in the array is always the parent. This can be retrieved in most cases by index 0.

BUT, if the previously called filter in Illuminate/Database/Eloquent/Collection.php:227 happens to filter the model with index 0 (which is perfectly possible, as otherwise the filter would be unnecessary), then we have an Undefined array key 0 error.

Therefore, I propose to change the given implementation to use reset() to get the first model, as this truly returns the first model in the array rather than the model with index 0.

[emielmolenaar]

Thanks for merging this. This fix is in the v5 branch, but not the v6 branch. Is there a specific reason for that?

[kohlerdominik]

Hi @emielmolenaar

Didn't realize that there's a v6 branch. I created a PR to merge the same commit to this branch: #552

[emielmolenaar]

@kohlerdominik All right, nice! Thanks for the PR. Hoping to see that one merged soon 😃