Why does R interpreter segfault on an underscore?

Question

This is more out of curiosity than anything else, but why does an _ cause the R interpreter to segfault? More generally, is there a list somewhere of input characters that will cause the R interpreter to die?

When the following script is sourced, it causes the R interpreter to segfault.

for  (_ in 1:50) {
}

This is reproducible by running R on the command line and then typing

source("Foo.r")

I am running 3.0.2. I am curious because it took me some time to isolate this bug.

Answer 1

This is a known bug in R 3.0.2 that has already been fixed and will be available in the next release, as documented in the read me file for the latest patched sources. The R development team determined that this bug is not OS-specific and that it only affects R 3.0.2.

Read the bug report above and the source code for more details.