User.merge puts array attribute in array

[dmironowicz]

Version

4.2.6

Context

Merging two User objects, such that only one of them has an array attribute with a given name, results in the merged user having this attribute as array of arrays.

Steps to reproduce

1. Create 1st User without any attributes
2. Create 2nd User with a single JsonArray attribute, e.g. roles = ["write"]
3. Call merge on the 1st user passing 2nd as parameter
4. Merged user has roles = [ ["write"] ]