warning: Parameter 1 to filefield_validate_associate_field() expected to be a reference

Using PHP 5.3.2 I'm seeing the following error when choosing an existing image via IMCE:

• ulwarning: Parameter 1 to filefield_validate_associate_field() expected to be a reference, value given /path/filefield_sources/filefield_sources.module on line 317.
• warning: array_merge() [function.array-merge]: Argument #2 is not an array in /path/filefield_sources/filefield_sources.module on line 317.
• warning: array_merge() [function.array-merge]: Argument #1 is not an array in /path/filefield_sources/filefield_sources.module on line 317.
• warning: array_merge() [function.array-merge]: Argument #1 is not an array in /path/filefield_sources/filefield_sources.module on line 317.
• warning: Parameter 1 to filefield_validate_is_image() expected to be a reference, value given in /path/filefield_sources/filefield_sources.module on line 317.
• warning: array_merge() [function.array-merge]: Argument #1 is not an array in /path/filefield_sources/filefield_sources.module on line 317.

Despite this error the module still works.

Versions:

- Drupal 6.17
- FileField 6.x-3.7
- IMCE 6.x-2.0-beta3
- FileField Sources 6.x.1.1

Related to #615862: Call-time pass-by-reference has been deprecated but instead it's expecting a reference.

Relevant Filefield issue: #755558: filefield_validate_associate_field generates a "ref needed value given" error with PHP 5.3