fix(parser): Don't panic on invalid UTF-8 values

Fixes #4473

src/lib.rs

@@ -156,4 +156,3 @@ mod util;
 
 const INTERNAL_ERROR_MSG: &str = "Fatal internal error. Please consider filing a bug \
                                   report at https://github.com/clap-rs/clap/issues";
-const INVALID_UTF8: &str = "unexpected invalid UTF-8 code point";

src/parser/features/suggestions.rs

@@ -35,7 +35,7 @@ where
 /// Returns a suffix that can be empty, or is the standard 'did you mean' phrase
 pub(crate) fn did_you_mean_flag<'a, 'help, I, T>(
     arg: &str,
-    remaining_args: &[&str],
+    remaining_args: &[&std::ffi::OsStr],
     longs: I,
     subcommands: impl IntoIterator<Item = &'a mut Command>,
 ) -> Option<(String, Option<String>)>

src/parser/parser.rs

@@ -20,7 +20,7 @@ use crate::parser::{ArgMatcher, SubCommand};
 use crate::parser::{Validator, ValueSource};
 use crate::util::Id;
 use crate::ArgAction;
-use crate::{INTERNAL_ERROR_MSG, INVALID_UTF8};
+use crate::INTERNAL_ERROR_MSG;
 
 pub(crate) struct Parser<'cmd> {
     cmd: &'cmd mut Command,
@@ -171,10 +171,8 @@ impl<'cmd> Parser<'cmd> {
                         }
                         ParseResult::NoMatchingArg { arg } => {
                             let _ = self.resolve_pending(matcher);
-                            let remaining_args: Vec<_> = raw_args
+                            let remaining_args: Vec<_> =
-                                .remaining(&mut args_cursor)
+                                raw_args.remaining(&mut args_cursor).collect();
-                                .map(|x| x.to_str().expect(INVALID_UTF8))
-                                .collect();
                             return Err(self.did_you_mean_error(
                                 &arg,
                                 matcher,
@@ -1523,7 +1521,7 @@ impl<'cmd> Parser<'cmd> {
         &mut self,
         arg: &str,
         matcher: &mut ArgMatcher,
-        remaining_args: &[&str],
+        remaining_args: &[&OsStr],
         trailing_values: bool,
     ) -> ClapError {
         debug!("Parser::did_you_mean_error: arg={}", arg);

tests/builder/utf8.rs

@@ -112,7 +112,6 @@ fn invalid_utf8_strict_invalid_short() {
 }
 
 #[test]
-#[should_panic]
 fn invalid_utf8_strict_invalid_long() {
     let m = Command::new("bad_utf8").try_get_matches_from(vec![
         OsString::from(""),