CHAR field with charset UTF8 and COLLATION UNICODE_CI_AI or UTF8 PHP is loading white spaces

[Delmar Wichnieski <delmar.delmar@xxxxxxxxx>]

Subject:
CHAR field with charset UTF8 and COLLATION UNICODE_CI_AI or UTF8 PHP is
loading white spaces
Example
'S   ' instead of 'S'

Environment
Windows 10
PHP 7.0.12 x64 VC14 TS
Apache Lounge 2.4.23 x64 VC14
firebird 2.5.5

configuration
php.ini
    default_charset = "UTF-8"
connection to the database
    ibase_connect ( "localhost:" DB, user, pw, "UTF8".
connection PHP script file in UTF-8
PHP script file with the test in UFT-8
response header
   Content-Type: text / html; charset = UTF-8
file.html
    <meta charset="UTF-8">

Migration in Firebird 2.5.5 charset ISO8859_1 collate PT_BR to UTF8 and
UNICODE_CI_AI (firebird 2.5.5)

DDL

SET SQL DIALECT 3;

SET NAMES UTF8;

SET CLIENTLIB 'C:\Program Files\Firebird\Firebird_2_5_5\WOW64\fbclient.dll';

CREATE DATABASE 'D:\MYDB_UTF8.FDB'
USER 'SYSDBA' PASSWORD 'A'
PAGE_SIZE 4096
DEFAULT CHARACTER SET UTF8 COLLATION UNICODE_CI_AI;

CREATE TABLE USUARIO (
    CODIGO         INTEGER NOT NULL,
    USUARIO        VARCHAR(20) CHARACTER SET UTF8 NOT NULL COLLATE
UNICODE_CI_AI,
    SENHA          VARCHAR(10) CHARACTER SET UTF8 NOT NULL COLLATE
UNICODE_CI_AI,
    CODCIDADE      INTEGER,
    ACESSOSISTEMA  CHAR(1) CHARACTER SET UTF8 COLLATE UNICODE_CI_AI,
    CPF            VARCHAR(12) CHARACTER SET UTF8 COLLATE UNICODE_CI_AI
);



Example
CHAR SIZE 1
in the database
    'S'
In php results
    'S   ' instead of 'S'
vardump (char_field)
string (4) "S   "

(Both ibase_query as PDO)

Its a configuration problem, bug or not full support to UFT-8?

Thank you very much!