Using "" as a target for .replace() is a really bad idea as it duplicates the replacement
for every character in the string. Add a testcase which triggered this and correct the
code to return the correct result.
(Bitbake rev: 3af1ecf049d2eed56f6d319dc7df6eb4a3d4eebc)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>