This blog is updated daily.
A general description is here.
In an Rd file, use of top-level \itemize{} inside a \value{} block is incorrectunnecessary and almost always gave a faulty conversion, silently. It is. Most cases are now detected and corrected, but gives a warning as such code will not work correctly in earlier versins of R.
Also, use of \code{} inside a code block such as \examples{} iswill give an errorneous conversion that is now detected and warned against.
R CMD build now also uses a Makevars file for cleaning up src/.
In setClass("C", contains="list"); x <- new("C", 1:3), x[2:3] now remains of class "C". So does rep(x, 2) or rep.int(x, 3).
unique.default() now preserves the "tzone" attribute on "POSIXct" objects.
If all the packages had dependency list of equal lengths, occasionally install.packages() would compute an incorrect sort order.