[Rd] readLines interaction with gsub different in R-dev

[Hugh Parsonage]

I was told to re-raise this issue with R-dev:

In the documentation of R-dev and R-3.4.3, under ?gsub

> replacement
>    ... For perl = TRUE only, it can also contain "\U" or "\L" to convert the rest of the replacement to upper or lower case and "\E" to end case conversion.

However, the following code runs differently:

tempf <- tempfile()
writeLines(enc2utf8("author: Amélie"), con = tempf, useBytes = TRUE)
entry <- readLines(tempf, encoding = "UTF-8")
gsub("(\\w)", "\\U\\1", entry, perl = TRUE)


"AUTHOR: AMÉLIE"  # R-3.4.3

"A"                              # R-dev



Best,

Hugh Parsonage.