Linked replicator in fieldset causes `Illegal string offset 'type'

[jawngee]

Bug Description

I have a collection that links to a fieldset that a few other collections use. The fieldset is a replicator with a variable number of sets.

Creating a new entry in that collection without adding anything to the linked replicator causes the Illegal string offset 'type' exception after saving it and navigating back to it.

Interestingly, this doesn't happen if the collection's blueprint only contains the linked replicator, but if you add other fields to the collection's blueprint the error occurs.

How to Reproduce

1. Create a field set that contains a replicator.
2. Create a new collection
3. In the new collection's blueprint add any field and add a field linked to the field set.
4. Create a new entry and save it without adding content to linked replicator field.
5. Navigate away and then back to the entry.

I've attached yaml configs: statamic-fieldset-bug.zip

Extra Detail

The error happend in line 47 of vendor/statamic/cms/src/FieldStypes/Replicator.php

I think the actual issue is further up the stack in:

cms/src/Fields/Field.php

Line 209 in 64eadfd

$value = $this->value ?? $this->defaultValue();

The issue is that an empty string makes it's way to line 47 of the Replicator, but because you are using a null coalescing operator (which doesn't work on empty strings) - the default value isn't being assigned.

So line 209 in Field.php should be rewritten with the elvis operator:

$value = $this->value ?: $this->defaultValue();

Environment

Statamic version: 3.0.19
Laravel: 8.10.0
PHP version: 7.4

Install method (choose one):

• Fresh install from statamic/statamic

[jawngee]

This is happening in Replicator.php too on line 102:

cms/src/Fieldtypes/Replicator.php

Line 102 in 67332fd

if (! $this->config("sets.{$set['type']}.fields")) {

It's the same deal. The value that makes it way to that method is an empty string where it's expecting an array. I had to add the following:

        if (empty($this->raw)) {
            return $this->raw;
        }

To Value.php at line 45:

cms/src/Fields/Value.php

Line 39 in 67332fd

public function value()

Obviously this is a deeper issue and I'm just whackamoling so I can get it to work. I read in other issues that having the linked replicator field named 'content' was causing issues before, but that issue was resolved in 3.x?

[jasonvarga]

This is indeed because you've named it content. Thanks!

[alexolder]

This is still an issue in 3.1.18 when trying to reference a replicator in a fieldset.