Description:
------------
Hello everyone.

When I try to change the interactive shell prompt using the command line (via the 
-d option), the trailing spaces doesn't show unless I begin the prompt with an 
non-alphanumeric character.

It works OK using the shorthand notation (#cli.prompt=test      ) inside the 
shell

Test script:
---------------
$ php -d cli.prompt="test       " -a
Interactive shell

test# spaces are not shown
test^C

$ php -d cli.prompt="-test       " -a
Interactive shell

-test       # now the prompt is ok
-test       ^C

$ php -d cli.prompt=" test       " -a
Interactive shell

 test       # also ok
 test       ^C


Expected result:
----------------
$ php -d cli.prompt="test       " -a
Interactive shell

test       # The trailing spaces should be honored.
test       ^C

Actual result:
--------------
$ php -d cli.prompt="test       " -a
Interactive shell

test# not honored
test^C