[9.x] bug fix, change array_merge to array_replace to prevent reindex

[kevindees]

Fixes issue where array [506 => null, 'name' => 'kevin'] is reindexed as [0 => null, 'name' => 'kevin']

[kevindees]

This fix does not provide any new functionality. The primary purpose is to prevent confusion when a database column has a numeric value that will be reindexed by PHP's array_merge. Adds:

1. Quality of life.
2. Removes unexpected/buggy behavior.

Example, previous behavior: array [506 => null, 'name' => 'kevin'] is reindexed as [0 => null, 'name' => 'kevin']. New behavior, array [506 => null, 'name' => 'kevin'] results in [506 => null, 'name' => 'kevin'].

[taylorotwell]

Hey there - so your problem is caused by having a column in your database with a purely numeric name? Is that correct?

[kevindees]

@taylorotwell

That is correct. I know numeric names are not accessible at the object level, but our legacy DB uses a numeric column name. If anything removing the reindex allows the issue to bubble to a more user-land-accessible level.