Custom guc variables not set properly

Question

I am trying to set a string variable say 'bdr_node_name' in the terminal using set command.

bdrdemo=# set bdr.node_name = 'node1';
SET
bdrdemo=# show bdr.node_name ;
bdr.node_name 
---------------
node1
(1 row)

Steps followed:

1)In postgresql.conf
bdr.node_name = 'node2'
2)In bdr.c
DefineCustomStringVariable("bdr.node_name",
                           "higher priority node during conflicts",
                           NULL,
                           &bdr_node_name,
                           " ", PGC_USERSET,
                           0,
                           NULL, NULL, NULL);
3)In bdr.h 
extern char *bdr_node_name;
4)In bdr_apply.c 
char *bdr_node_name;

While trying to print the bdr_node_name value in log file it shows the default value set in postgresql.conf i.e. node2. The value assigned using set command is not being printed. But the show command displays the correct value. How is that possible? Am I missing something?