'excludeSearch' is ignored when use search by API. regression

I'm using version 6.0.12. Bug is in this version, but it was not in 6.0.10.

Steps to reproduce:

1. Call the "host.get" REST API with the following Params.

   {
       "excludeSearch": 1,
       "output": [
           "hostid",
           "host"
       ],
       "search": {
           "host": "Zabbix"
       }
   } 

1. Here Zabbix will ignore the "excludeSearch" param and it will return hosts that contain the word 'zabbix' instead of excluding hosts that contain that word

Expected:
I would expect Zabbix to exclude what I put in the "search" param when I set the 'excludeSearch' param to true, but Zabbix does not. it totally ignores the value of the 'excludeSearch' and it just assumes it is always set to 'false' even if you change its value to true.