ckeditor/ckeditor-dev — pull request #60 by niklam (2013-10-14 06:07:06+00:00)
Title: #9929: [Chrome 23] &nbsp; is created when deleting character and typing ...

...common space

It seems as is a result of altering source for checkStartOfBlock()/checkEndOfBlock(). Changing order of checks in if checkStartOfBlock()/checkEndOfBlock() are run only when necessary, not every time del/backspace is pressed.