Search and replace is broken

[Treit]

Started with this content in the editor:

This is a test This is a test This is a test This is a test

Trying to replace 'this' with 'foo' in the string resulted in this garbled mess:

foo is a test Tfoois a test Thfoos a test Thifoo a test

See below:

[lhecker]

Aha! I think this shows that shortening the content is broken. This is almost certainly the same issue as #58. I'll keep them separate as they represent separate test cases. Thanks!

[Treit]

I pulled the latest code and rebuilt edit and I can still reproduce this issue.

The deadlock issue #58 does appear to be fixed, but this issue where the replace garbles the text still seems to be there.