Panic when filename of staged file contains non-ASCII character

[5hir0kur0]

Description

In some situations with non-ASCII file names, gitu panics.

Reproduction

1. Check out master branch (tested with commit 5dbf6ed).
2. Run the following shell commands

touch 'bläh'
git add 'bläh'
RUST_BACKTRACE=1 cargo -q run 2>err; echo "exit code: $?; error:"; cat err

The following panic backtrace is printed:

exit code: 101; error:

thread 'main' panicked at src/git/mod.rs:156:64:
called `Result::unwrap()` on an `Err` value: Expected "<diff header path prefix (' a/...' or ' b/...')>" at byte 11
stack backtrace:
   0: rust_begin_unwind
             at /rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/std/src/panicking.rs:692:5
   1: core::panicking::panic_fmt
             at /rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/core/src/panicking.rs:75:14
   2: core::result::unwrap_failed
             at /rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/core/src/result.rs:1704:5
   3: core::result::Result<T,E>::unwrap
             at ~/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/result.rs:1109:23
   4: gitu::git::diff_staged
             at ./src/git/mod.rs:156:21
   5: gitu::screen::status::create::{{closure}}
             at ./src/screen/status.rs:94:26
   6: <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call
             at ~/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/src/boxed.rs:2007:9
   7: gitu::screen::Screen::update
             at ./src/screen/mod.rs:208:22
   8: gitu::screen::Screen::new
             at ./src/screen/mod.rs:58:9
   9: gitu::screen::status::create
             at ./src/screen/status.rs:18:5
  10: gitu::state::State::create
             at ./src/state.rs:76:26
  11: gitu::run
             at ./src/lib.rs:83:21
  12: gitu::main
             at ./src/main.rs:34:5
  13: core::ops::function::FnOnce::call_once
             at ~/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[eMPee584]

Same panic with diff.noprefix=true in /etc/gitconfig by the way..

[poelzi]

Got this when trying to open my music folder (git-annex)

trace: 
   0: gitu::main::{{closure}}
   1: std::panicking::rust_panic_with_hook
   2: std::panicking::begin_panic_handler::{{closure}}
   3: std::sys::backtrace::__rust_end_short_backtrace
   4: rust_begin_unwind
   5: core::panicking::panic_fmt
   6: core::result::unwrap_failed
   7: gitu::git::diff_staged
   8: gitu::screen::status::create::{{closure}}
   9: gitu::screen::Screen::update
  10: gitu::screen::Screen::new
  11: gitu::screen::status::create
  12: gitu::run
  13: gitu::setup_term_and_run
  14: gitu::term::alternate_screen
  15: gitu::main
  16: std::sys::backtrace::__rust_begin_short_backtrace
  17: std::rt::lang_start::{{closure}}
  18: std::rt::lang_start_internal
  19: main
  20: __libc_start_call_main
  21: __libc_start_main_alias_1
  22: _start
``

[altsem]

All of these issues should be fixed in https://github.com/altsem/gitu/commit/e40cfc8870168b70cee6d32c32ea5e7086fac42e.

I noted that diffs without a prefix are not possible to feed back into git (when e.g. staging), so that remains to figure out.