Cargo install panics on some non-ASCII input

[timcryt]

Problem

cargo install panics on some non-ASCII input.

I executed this command: cargo install greĉ.

Then cargo paniced with message:

thread 'main' panicked at 'byte index 4 is not a char boundary; it is inside 'ĉ' (bytes 3..5) of `greĉ`', library/core/src/str/mod.rs:127:5

Steps

1. Execute cargo install greĉ

Possible Solution(s)

This line

_ => format!("{}/{}{}{}", &dep_name[0..2], &dep_name[2..4], slash, name),

causes the panic.

If one rewrite this code avoiding division on possibly invalid position issue will be solved.

Notes

Backtrace:

   0: rust_begin_unwind
             at /rustc/801821d1560f84e4716fcbd9244ec959320a13d5/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/801821d1560f84e4716fcbd9244ec959320a13d5/library/core/src/panicking.rs:142:14
   2: core::str::slice_error_fail_rt
   3: core::ops::function::FnOnce::call_once
             at /rustc/801821d1560f84e4716fcbd9244ec959320a13d5/library/core/src/ops/function.rs:248:5
   4: core::intrinsics::const_eval_select
             at /rustc/801821d1560f84e4716fcbd9244ec959320a13d5/library/core/src/intrinsics.rs:2485:5
   5: core::str::slice_error_fail
             at /rustc/801821d1560f84e4716fcbd9244ec959320a13d5/library/core/src/str/mod.rs:86:9
   6: cargo_util::registry::make_dep_path
   7: <cargo::sources::registry::index::RegistryIndex>::summaries
   8: <cargo::sources::registry::index::RegistryIndex>::query_inner_with_online
   9: <cargo::sources::registry::RegistrySource as cargo::core::source::Source>::query
  10: cargo::ops::common_for_install_and_uninstall::select_dep_pkg::<alloc::boxed::Box<dyn cargo::core::source::Source>>
  11: <cargo::ops::cargo_install::InstallablePackage>::new
  12: cargo::ops::cargo_install::install
  13: cargo::commands::install::exec
  14: cargo::cli::main
  15: cargo::main

Version

cargo 1.65.0-nightly (efd4ca3dc 2022-08-12)

[weihanglo]

Please see the comment if you want to do an enhancement: #10994 (comment), specifically figuring out how crates.io handles ASCII crate names.