Description:
------------
pg_fetch_* returns space string (e.g. ' ') when returning a empty sting 
''
Postgres is returning an empty string and pg_fetch is 
changing the return value.
Empty string is only return if the result is 
caste as a varchar in the sql 
e.g."SELECT test_thing::varchar".

Test script:
---------------
//In DB
CREATE TABLE test ( test_thing VARCHAR(5) NOT NULL DEFAULT '');
INSERT INTO test VALUES ('');

//code
$testing = pg_query($db_conn,"SELECT test_thing FROM test WHERE test_thing='');
print_r(pg_fetch_all($testing));
print 'testing'.pg_fetch_result($testing,0,0).'this';

Expected result:
----------------
array(1) {
[0]=
  array(1) {
    
['test_thing']=
    string(0) 
''
}
}

testingthis
 

Actual result:
--------------
array(1) {
[0]=
  array(1) {
    
['test_thing']=
    string(1) ' 
'
}
}

testing this