Inconsistent behavior between str_split and strsplit

The documentation for str_split in the stringr package states that for the pattern argument:

If "" splits into individual characters.

which suggests it behaves the same as strsplit in this regard. However,

library(stringr)
str_split("abcab","")
[[1]]
[1] ""  "a" "b" "c" "a" "b"

with a leading empty string. This compares with,

strsplit("abcab","")
[[1]]
[1] "a" "b" "c" "a" "b"

Leading empty strings seems to be normal behavior when splitting on non-empty strings,

strsplit("abcab","ab")
[[1]]
[1] ""  "c"

but even then, str_split generates an 'extra' trailing empty string:

str_split("abcab","ab")
[[1]]
[1] ""  "c" "" 

Is this discrepancy a bug, feature, an error in the documentation or just a different notion of what's 'expected behavior'?