From Bugzilla Helper:
User-Agent: Mozilla/5.0 (compatible; HornyPorny 1.0)

Description of problem:
The bundled readline handles multiline prompts in a non-working way.
When typing in command, it wraps the line at the wrong position, it
seem to calculate wrong value for the length of the last line of the
prompt, and the result it gets depends on all the other rows of the
prompt. Combined with colours, and their control codes, the output
gets totally clobbered.

Version-Release number of selected component (if applicable):
bash-3.0-2

How reproducible:
Always

Steps to Reproduce:
1. PS1="foo\nbar"
2. insert enough text to fill the line
    

Actual Results:  The line wraps 2 characters before the end of the line.

Expected Results:  The line should've wrapped exactly at the end.

Additional info:

If use ^V^J instead of \n, the line wraps 1 character before the end.