This blog is updated daily..
A general description is here.
More of the installation and checking process will work even when ‘TMPDIR’ is set to a path containing spaces, but this is not recommeneded and external software (such as ‘texi2dvi’) may fail.
‘file.show()’ and ‘edit()’ are now more likely to work on file paths containing spaces. (Where external utilities are used, not the norm on Windows nor in ‘R.app’, which should previously have worked.)