String::replace() broken by recent commits

[mike-s123]

@me-no-dev

Pulled the latest head (4d95e3a), String::replace() is broken.

String foo = "/sd/ctl00000000.rrd";
foo.replace("/sd/","/");

Should result in foo containing "/ctl00000000.rrd". Instead, it results in "/ctl00000000. 0."

Going back in time to before the recent String commits...

git reset --hard 6e7cc521

fixes the issue.