[R-SIG-Mac] ANSI escape weirdness on M1 (libedit issue?)

[Gábor Csárdi]

Anyone else noticed some weirdness with the arm build when the prompt
has ANSI escape codes?

E.g. in a terminal run this
options(prompt = "\033[1m> \033[0m")

and then at the new prompt type in some longer word and press CTRL+A.
The cursor does not go back to the beginning of the line, probably
because the width of the prompt is not calculated correctly by the
underlying system library.

readline is not listed at https://mac.r-project.org/libs-arm64/ while
it is listed among the intel libs. Does that mean that R uses libedit
on arm64? Is this an issue with libedit?

Thanks,
Gabor