rm.prefix() and rm.suffix() to remove a given prefix or suffix from character vector elements.whichRepeated(), whichNA(), whichMin()/whichMax() when loc = "all" and repeats() now don't attempt to preserve names when no indices or duplicates are found, respectively.
The C code for whichRepeated() now avoids passing an invalid data pointer from a 0-length vector to memcpy(), which previously caused undefined behaviour. Thanks to Prof. Brian D. Ripley for reporting.