segfault when ht_xptr is missing for dict environment

[qinwf]

> k = collections::dict()
> k$ht_xptr = NULL
> k$get("test")

 *** caught segfault ***
address 0x108030040, cause 'memory not mapped'

Traceback:
 1: k$get("test")

Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace
Selection:

Maybe the C code should lock the environment binding or check the existent of ht_xptr or hide ht_xptr from users?

[randy3k]

It is expected though.

[qinwf]

OK

[randy3k]

By the way, why you wanted to access the internal variables?

[qinwf]

Just hanging around the c code and accidentally find a way to crash R.

It is brilliant to use the cons-list as a queue by the way.

But it is not a safe abstraction. I think the R package api should never crash user sessions. Instead, they should throw an R error for these cases.

[randy3k]

Let’s keep it open.