When NULL is returned, is the previous value returned?

Question

go

Code
https://play.golang.org/p/eFIs1MRxHt
Please tell me I found a bug
When I request data via api
[[email protected] ~]#
[[email protected] ~]# curl -i -u freeswitch:directory -d "method=get_user&name=4" 0.0.0.0:9090/directory
HTTP/1.1 200 OK
Content-Type: application/json
Date: Tue, 24 Oct 2017 18:50:15 GMT
Content-Length: 40
{"username" :"","password":"","state":""}
I get an empty string
after that I will ask where the data is
[[email protected] ~]# curl -i -u freeswitch:directory -d "method =get_user&name=445" 0.0.0.0:9090/directory
HTTP/1.1 200 OK
Content-Type: application/json
Date: Tue, 24 Oct 2017 18:51:13 GMT
Content-Length: 53
{"username":"445","password":"1234","state":"active"}[
then re-request
[[email protected] 216530-2 ~]# curl -i -u freeswitch:directory -d "method=get_user&name=4" 0.0.0.0:9090/directory
HTTP/1.1 200 OK
Content-Type: application/json
Date: Tue, 24 Oct 2017 18 :51:35 GMT
Content-Length: 53
{"username":"445","password":"1234","state":"active"}
and instead of empty values, the previous value is returned
help me understand where the error is thanks in advance

Answer 1

You have rec as a global variable. Move its declaration inside the get_user() function and others, if any.

Answer 2

Even without looking at the code: variables must be cleared :-)