Change environment variable getters to error recoverably
This PR changes the standard library environment variable getter functions to error recoverably (i.e. not panic) when given an invalid value.
On some platforms, it is invalid for environment variable names to contain `'\0'` or `'='`, or for their values to contain `'\0'`. Currently, the standard library panics when manipulating environment variables with names or values that violate these invariants. However, this behavior doesn't make a lot of sense, at least in the case of getters. If the environment variable is missing, the standard library just returns an error value, rather than panicking. It doesn't make sense to treat the case where the variable is invalid any differently from that. See the [internals thread](https://internals.rust-lang.org/t/why-should-std-var-panic/14847) for discussion. Thus, this PR changes the functions to error recoverably in this case as well.
If desired, I could change the functions that manipulate environment variables in other ways as well. I didn't do that here because it wasn't entirely clear what to change them to. Should they error silently or do something else? If someone tells me how to change them, I'm happy to implement the changes.
This fixes#86082, an ICE that arises from the current behavior. It also adds a regression test to make sure the ICE does not occur again in the future.
`@rustbot` label +T-libs
r? `@joshtriplett`
Before this, `std`'s env var getter functions would panic on
receiving certain invalid inputs. This commit makes them
return a `None` or `Err` instead.
Add doc alias for `chdir` to `std::env::set_current_dir`
Searching for `chdir` in the Rust documentation produces no useful
results.
I wrote some code recently that called `libc::chdir` and manually
handled errors, because I didn't realize that the safe
`std::env::set_current_dir` existed. I searched for `chdir` and
`change_dir` and `change_directory` (the latter two based on the
precedent of unabbreviating set by `create_dir`), and I also read
through `std::fs` expecting to potentially find it there. Given that
none of those led to `std::env::set_current_dir`, I think that provides
sufficient justification to add this specific alias.
Remove `sys::args::Args::inner_debug` and use `Debug` instead
This removes the method `sys::args::Args::inner_debug` on all platforms and implements `Debug` for `Args` instead.
I believe this creates a more natural API for the different platforms under `sys`: export a type `Args: Debug + Iterator + ...` vs. `Args: Iterator + ...` and with a method `inner_debug`.
vars() rather than vars function
Co-authored-by: Joshua Nelson <joshua@yottadb.com>
Use [xxx()] rather than the [xxx] function
Co-authored-by: Joshua Nelson <joshua@yottadb.com>
Env text representation of function intra-doc link
Suggested by @jyn514
Link join_paths in env doc for parity
Change xxx to env::xxx for lib env doc
Add link requsted by @jyn514
Fix doc build with same link
Co-authored-by: Joshua Nelson <joshua@yottadb.com>
Fix missing intra-doc link
Fix added whitespace in doc
Co-authored-by: Joshua Nelson <joshua@yottadb.com>
Add brackets for `join_paths`
Co-authored-by: Joshua Nelson <joshua@yottadb.com>
Use unused link join_paths
Removed same link for join_paths
Co-authored-by: Joshua Nelson <joshua@yottadb.com>
Remove unsed link join_paths
