Adding upstream version 1.69.0+dfsg1.upstream/1.69.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 265 insertions, 88 deletions

diff --git a/vendor/syn/src/buffer.rs b/vendor/syn/src/buffer.rs
index 161b614c8..0d5cf30d5 100644
--- a/vendor/syn/src/buffer.rs
+++ b/vendor/syn/src/buffer.rs
@@ -14,6 +14,7 @@
 use crate::proc_macro as pm;
 use crate::Lifetime;
 use proc_macro2::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
+use std::cmp::Ordering;
 use std::marker::PhantomData;
 
 /// Internal type which is used instead of `TokenTree` to represent a token tree
@@ -25,7 +26,8 @@ enum Entry {
     Ident(Ident),
     Punct(Punct),
     Literal(Literal),
-    End,
+    // End entries contain the offset (negative) to the start of the buffer.
+    End(isize),
 }
 
 /// A buffer that can be efficiently traversed multiple times, unlike
@@ -48,10 +50,10 @@ impl TokenBuffer {
                 TokenTree::Literal(literal) => entries.push(Entry::Literal(literal)),
                 TokenTree::Group(group) => {
                     let group_start_index = entries.len();
-                    entries.push(Entry::End); // we replace this below
+                    entries.push(Entry::End(0)); // we replace this below
                     Self::recursive_new(entries, group.stream());
                     let group_end_index = entries.len();
-                    entries.push(Entry::End);
+                    entries.push(Entry::End(-(group_end_index as isize)));
                     let group_end_offset = group_end_index - group_start_index;
                     entries[group_start_index] = Entry::Group(group, group_end_offset);
                 }
@@ -77,7 +79,7 @@ impl TokenBuffer {
     pub fn new2(stream: TokenStream) -> Self {
         let mut entries = Vec::new();
         Self::recursive_new(&mut entries, stream);
-        entries.push(Entry::End);
+        entries.push(Entry::End(-(entries.len() as isize)));
         Self {
             entries: entries.into_boxed_slice(),
         }
@@ -127,7 +129,7 @@ impl<'a> Cursor<'a> {
         // object in global storage.
         struct UnsafeSyncEntry(Entry);
         unsafe impl Sync for UnsafeSyncEntry {}
-        static EMPTY_ENTRY: UnsafeSyncEntry = UnsafeSyncEntry(Entry::End);
+        static EMPTY_ENTRY: UnsafeSyncEntry = UnsafeSyncEntry(Entry::End(0));
 
         Cursor {
             ptr: &EMPTY_ENTRY.0,
@@ -144,7 +146,7 @@ impl<'a> Cursor<'a> {
         // past it, unless `ptr == scope`, which means that we're at the edge of
         // our cursor's scope. We should only have `ptr != scope` at the exit
         // from None-delimited groups entered with `ignore_none`.
-        while let Entry::End = *ptr {
+        while let Entry::End(_) = *ptr {
             if ptr == scope {
                 break;
             }
@@ -292,7 +294,7 @@ impl<'a> Cursor<'a> {
             Entry::Literal(literal) => (literal.clone().into(), 1),
             Entry::Ident(ident) => (ident.clone().into(), 1),
             Entry::Punct(punct) => (punct.clone().into(), 1),
-            Entry::End => return None,
+            Entry::End(_) => return None,
         };
 
         let rest = unsafe { Cursor::create(self.ptr.add(len), self.scope) };
@@ -307,7 +309,7 @@ impl<'a> Cursor<'a> {
             Entry::Literal(literal) => literal.span(),
             Entry::Ident(ident) => ident.span(),
             Entry::Punct(punct) => punct.span(),
-            Entry::End => Span::call_site(),
+            Entry::End(_) => Span::call_site(),
         }
     }
 
@@ -317,7 +319,7 @@ impl<'a> Cursor<'a> {
     /// This method treats `'lifetimes` as a single token.
     pub(crate) fn skip(self) -> Option<Cursor<'a>> {
         let len = match self.entry() {
-            Entry::End => return None,
+            Entry::End(_) => return None,
 
             // Treat lifetimes as a single tt for the purposes of 'skip'.
             Entry::Punct(punct) if punct.as_char() == '\'' && punct.spacing() == Spacing::Joint => {
@@ -347,9 +349,17 @@ impl<'a> Eq for Cursor<'a> {}
 
 impl<'a> PartialEq for Cursor<'a> {
     fn eq(&self, other: &Self) -> bool {
-        let Cursor { ptr, scope, marker } = self;
-        let _ = marker;
-        *ptr == other.ptr && *scope == other.scope
+        self.ptr == other.ptr
+    }
+}
+
+impl<'a> PartialOrd for Cursor<'a> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        if same_buffer(*self, *other) {
+            Some(self.ptr.cmp(&other.ptr))
+        } else {
+            None
+        }
     }
 }
 
@@ -357,6 +367,22 @@ pub(crate) fn same_scope(a: Cursor, b: Cursor) -> bool {
     a.scope == b.scope
 }
 
+pub(crate) fn same_buffer(a: Cursor, b: Cursor) -> bool {
+    unsafe {
+        match (&*a.scope, &*b.scope) {
+            (Entry::End(a_offset), Entry::End(b_offset)) => {
+                a.scope.offset(*a_offset) == b.scope.offset(*b_offset)
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+
+#[cfg(any(feature = "full", feature = "derive"))]
+pub(crate) fn cmp_assuming_same_buffer(a: Cursor, b: Cursor) -> Ordering {
+    a.ptr.cmp(&b.ptr)
+}
+
 pub(crate) fn open_span_of_group(cursor: Cursor) -> Span {
     match cursor.entry() {
         Entry::Group(group, _) => group.span_open(),
diff --git a/vendor/syn/src/drops.rs b/vendor/syn/src/drops.rs
new file mode 100644
index 000000000..89b42d82e
--- /dev/null
+++ b/vendor/syn/src/drops.rs
@@ -0,0 +1,58 @@
+use std::iter;
+use std::mem::ManuallyDrop;
+use std::ops::{Deref, DerefMut};
+use std::option;
+use std::slice;
+
+#[repr(transparent)]
+pub(crate) struct NoDrop<T: ?Sized>(ManuallyDrop<T>);
+
+impl<T> NoDrop<T> {
+    pub(crate) fn new(value: T) -> Self
+    where
+        T: TrivialDrop,
+    {
+        NoDrop(ManuallyDrop::new(value))
+    }
+}
+
+impl<T: ?Sized> Deref for NoDrop<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<T: ?Sized> DerefMut for NoDrop<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+pub(crate) trait TrivialDrop {}
+
+impl<T> TrivialDrop for iter::Empty<T> {}
+impl<'a, T> TrivialDrop for slice::Iter<'a, T> {}
+impl<'a, T> TrivialDrop for slice::IterMut<'a, T> {}
+impl<'a, T> TrivialDrop for option::IntoIter<&'a T> {}
+impl<'a, T> TrivialDrop for option::IntoIter<&'a mut T> {}
+
+#[test]
+fn test_needs_drop() {
+    use std::mem::needs_drop;
+
+    struct NeedsDrop;
+
+    impl Drop for NeedsDrop {
+        fn drop(&mut self) {}
+    }
+
+    assert!(needs_drop::<NeedsDrop>());
+
+    // Test each of the types with a handwritten TrivialDrop impl above.
+    assert!(!needs_drop::<iter::Empty<NeedsDrop>>());
+    assert!(!needs_drop::<slice::Iter<NeedsDrop>>());
+    assert!(!needs_drop::<slice::IterMut<NeedsDrop>>());
+    assert!(!needs_drop::<option::IntoIter<&NeedsDrop>>());
+    assert!(!needs_drop::<option::IntoIter<&mut NeedsDrop>>());
+}
diff --git a/vendor/syn/src/error.rs b/vendor/syn/src/error.rs
index 609cc086f..e301367d5 100644
--- a/vendor/syn/src/error.rs
+++ b/vendor/syn/src/error.rs
@@ -134,12 +134,16 @@ impl Error {
     /// }
     /// ```
     pub fn new<T: Display>(span: Span, message: T) -> Self {
-        Error {
-            messages: vec![ErrorMessage {
-                start_span: ThreadBound::new(span),
-                end_span: ThreadBound::new(span),
-                message: message.to_string(),
-            }],
+        return new(span, message.to_string());
+
+        fn new(span: Span, message: String) -> Error {
+            Error {
+                messages: vec![ErrorMessage {
+                    start_span: ThreadBound::new(span),
+                    end_span: ThreadBound::new(span),
+                    message,
+                }],
+            }
         }
     }
 
@@ -158,15 +162,19 @@ impl Error {
     /// `ParseStream::error`)!
     #[cfg(feature = "printing")]
     pub fn new_spanned<T: ToTokens, U: Display>(tokens: T, message: U) -> Self {
-        let mut iter = tokens.into_token_stream().into_iter();
-        let start = iter.next().map_or_else(Span::call_site, |t| t.span());
-        let end = iter.last().map_or(start, |t| t.span());
-        Error {
-            messages: vec![ErrorMessage {
-                start_span: ThreadBound::new(start),
-                end_span: ThreadBound::new(end),
-                message: message.to_string(),
-            }],
+        return new_spanned(tokens.into_token_stream(), message.to_string());
+
+        fn new_spanned(tokens: TokenStream, message: String) -> Error {
+            let mut iter = tokens.into_iter();
+            let start = iter.next().map_or_else(Span::call_site, |t| t.span());
+            let end = iter.last().map_or(start, |t| t.span());
+            Error {
+                messages: vec![ErrorMessage {
+                    start_span: ThreadBound::new(start),
+                    end_span: ThreadBound::new(end),
+                    message,
+                }],
+            }
         }
     }
 
@@ -288,12 +296,16 @@ pub fn new_at<T: Display>(scope: Span, cursor: Cursor, message: T) -> Error {
 
 #[cfg(all(feature = "parsing", any(feature = "full", feature = "derive")))]
 pub fn new2<T: Display>(start: Span, end: Span, message: T) -> Error {
-    Error {
-        messages: vec![ErrorMessage {
-            start_span: ThreadBound::new(start),
-            end_span: ThreadBound::new(end),
-            message: message.to_string(),
-        }],
+    return new2(start, end, message.to_string());
+
+    fn new2(start: Span, end: Span, message: String) -> Error {
+        Error {
+            messages: vec![ErrorMessage {
+                start_span: ThreadBound::new(start),
+                end_span: ThreadBound::new(end),
+                message,
+            }],
+        }
     }
 }
 
diff --git a/vendor/syn/src/generics.rs b/vendor/syn/src/generics.rs
index 9c2802f87..6d4fe847e 100644
--- a/vendor/syn/src/generics.rs
+++ b/vendor/syn/src/generics.rs
@@ -828,6 +828,31 @@ pub mod parsing {
         }
     }
 
+    impl TypeParamBound {
+        pub(crate) fn parse_multiple(
+            input: ParseStream,
+            allow_plus: bool,
+        ) -> Result<Punctuated<Self, Token![+]>> {
+            let mut bounds = Punctuated::new();
+            loop {
+                bounds.push_value(input.parse()?);
+                if !(allow_plus && input.peek(Token![+])) {
+                    break;
+                }
+                bounds.push_punct(input.parse()?);
+                if !(input.peek(Ident::peek_any)
+                    || input.peek(Token![::])
+                    || input.peek(Token![?])
+                    || input.peek(Lifetime)
+                    || input.peek(token::Paren))
+                {
+                    break;
+                }
+            }
+            Ok(bounds)
+        }
+    }
+
     #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
     impl Parse for TraitBound {
         fn parse(input: ParseStream) -> Result<Self> {
diff --git a/vendor/syn/src/lib.rs b/vendor/syn/src/lib.rs
index 81f03e1b5..e47ba28c6 100644
--- a/vendor/syn/src/lib.rs
+++ b/vendor/syn/src/lib.rs
@@ -250,13 +250,14 @@
 //!   dynamic library libproc_macro from rustc toolchain.
 
 // Syn types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/syn/1.0.102")]
+#![doc(html_root_url = "https://docs.rs/syn/1.0.107")]
 #![cfg_attr(doc_cfg, feature(doc_cfg))]
 #![allow(non_camel_case_types)]
 #![allow(
     clippy::bool_to_int_with_if,
     clippy::cast_lossless,
     clippy::cast_possible_truncation,
+    clippy::cast_possible_wrap,
     clippy::cast_ptr_alignment,
     clippy::default_trait_access,
     clippy::doc_markdown,
@@ -264,8 +265,8 @@
     clippy::explicit_auto_deref,
     clippy::if_not_else,
     clippy::inherent_to_string,
+    clippy::items_after_statements,
     clippy::large_enum_variant,
-    clippy::let_underscore_drop,
     clippy::manual_assert,
     clippy::match_on_vec_items,
     clippy::match_same_arms,
@@ -428,6 +429,7 @@ pub use crate::path::{
 #[cfg(feature = "parsing")]
 #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
 pub mod buffer;
+mod drops;
 #[cfg(feature = "parsing")]
 #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
 pub mod ext;
diff --git a/vendor/syn/src/path.rs b/vendor/syn/src/path.rs
index 742273afd..6cdb43ac5 100644
--- a/vendor/syn/src/path.rs
+++ b/vendor/syn/src/path.rs
@@ -89,9 +89,8 @@ impl PathArguments {
         }
     }
 
-    #[cfg(feature = "parsing")]
-    fn is_none(&self) -> bool {
-        match *self {
+    pub fn is_none(&self) -> bool {
+        match self {
             PathArguments::None => true,
             PathArguments::AngleBracketed(_) | PathArguments::Parenthesized(_) => false,
         }
diff --git a/vendor/syn/src/punctuated.rs b/vendor/syn/src/punctuated.rs
index 0fe1078cf..b7d0185e8 100644
--- a/vendor/syn/src/punctuated.rs
+++ b/vendor/syn/src/punctuated.rs
@@ -32,6 +32,7 @@ use std::option;
 use std::slice;
 use std::vec;
 
+use crate::drops::{NoDrop, TrivialDrop};
 #[cfg(feature = "parsing")]
 use crate::parse::{Parse, ParseStream, Result};
 #[cfg(feature = "parsing")]
@@ -104,10 +105,10 @@ impl<T, P> Punctuated<T, P> {
     /// Returns an iterator over borrowed syntax tree nodes of type `&T`.
     pub fn iter(&self) -> Iter<T> {
         Iter {
-            inner: Box::new(PrivateIter {
+            inner: Box::new(NoDrop::new(PrivateIter {
                 inner: self.inner.iter(),
                 last: self.last.as_ref().map(Box::as_ref).into_iter(),
-            }),
+            })),
         }
     }
 
@@ -115,10 +116,10 @@ impl<T, P> Punctuated<T, P> {
     /// `&mut T`.
     pub fn iter_mut(&mut self) -> IterMut<T> {
         IterMut {
-            inner: Box::new(PrivateIterMut {
+            inner: Box::new(NoDrop::new(PrivateIterMut {
                 inner: self.inner.iter_mut(),
                 last: self.last.as_mut().map(Box::as_mut).into_iter(),
-            }),
+            })),
         }
     }
 
@@ -721,13 +722,13 @@ pub struct Iter<'a, T: 'a> {
     // The `Item = &'a T` needs to be specified to support rustc 1.31 and older.
     // On modern compilers we would be able to write just IterTrait<'a, T> where
     // Item can be inferred unambiguously from the supertrait.
-    inner: Box<dyn IterTrait<'a, T, Item = &'a T> + 'a>,
+    inner: Box<NoDrop<dyn IterTrait<'a, T, Item = &'a T> + 'a>>,
 }
 
 trait IterTrait<'a, T: 'a>:
     DoubleEndedIterator<Item = &'a T> + ExactSizeIterator<Item = &'a T>
 {
-    fn clone_box(&self) -> Box<dyn IterTrait<'a, T, Item = &'a T> + 'a>;
+    fn clone_box(&self) -> Box<NoDrop<dyn IterTrait<'a, T, Item = &'a T> + 'a>>;
 }
 
 struct PrivateIter<'a, T: 'a, P: 'a> {
@@ -735,10 +736,17 @@ struct PrivateIter<'a, T: 'a, P: 'a> {
     last: option::IntoIter<&'a T>,
 }
 
+impl<'a, T, P> TrivialDrop for PrivateIter<'a, T, P>
+where
+    slice::Iter<'a, (T, P)>: TrivialDrop,
+    option::IntoIter<&'a T>: TrivialDrop,
+{
+}
+
 #[cfg(any(feature = "full", feature = "derive"))]
 pub(crate) fn empty_punctuated_iter<'a, T>() -> Iter<'a, T> {
     Iter {
-        inner: Box::new(iter::empty()),
+        inner: Box::new(NoDrop::new(iter::empty())),
     }
 }
 
@@ -813,10 +821,14 @@ impl<'a, T, P> Clone for PrivateIter<'a, T, P> {
 impl<'a, T, I> IterTrait<'a, T> for I
 where
     T: 'a,
-    I: DoubleEndedIterator<Item = &'a T> + ExactSizeIterator<Item = &'a T> + Clone + 'a,
+    I: DoubleEndedIterator<Item = &'a T>
+        + ExactSizeIterator<Item = &'a T>
+        + Clone
+        + TrivialDrop
+        + 'a,
 {
-    fn clone_box(&self) -> Box<dyn IterTrait<'a, T, Item = &'a T> + 'a> {
-        Box::new(self.clone())
+    fn clone_box(&self) -> Box<NoDrop<dyn IterTrait<'a, T, Item = &'a T> + 'a>> {
+        Box::new(NoDrop::new(self.clone()))
     }
 }
 
@@ -826,7 +838,7 @@ where
 ///
 /// [module documentation]: self
 pub struct IterMut<'a, T: 'a> {
-    inner: Box<dyn IterMutTrait<'a, T, Item = &'a mut T> + 'a>,
+    inner: Box<NoDrop<dyn IterMutTrait<'a, T, Item = &'a mut T> + 'a>>,
 }
 
 trait IterMutTrait<'a, T: 'a>:
@@ -839,10 +851,17 @@ struct PrivateIterMut<'a, T: 'a, P: 'a> {
     last: option::IntoIter<&'a mut T>,
 }
 
+impl<'a, T, P> TrivialDrop for PrivateIterMut<'a, T, P>
+where
+    slice::IterMut<'a, (T, P)>: TrivialDrop,
+    option::IntoIter<&'a mut T>: TrivialDrop,
+{
+}
+
 #[cfg(any(feature = "full", feature = "derive"))]
 pub(crate) fn empty_punctuated_iter_mut<'a, T>() -> IterMut<'a, T> {
     IterMut {
-        inner: Box::new(iter::empty()),
+        inner: Box::new(NoDrop::new(iter::empty())),
     }
 }
 
diff --git a/vendor/syn/src/ty.rs b/vendor/syn/src/ty.rs
index 4068be3c7..8c841e2f7 100644
--- a/vendor/syn/src/ty.rs
+++ b/vendor/syn/src/ty.rs
@@ -337,7 +337,7 @@ pub mod parsing {
     use crate::ext::IdentExt;
     use crate::parse::{Parse, ParseStream, Result};
     use crate::path;
-    use proc_macro2::{Punct, Spacing, TokenTree};
+    use proc_macro2::{Punct, Spacing, Span, TokenTree};
 
     #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
     impl Parse for Type {
@@ -546,13 +546,17 @@ pub mod parsing {
             || lookahead.peek(Token![<])
         {
             let dyn_token: Option<Token![dyn]> = input.parse()?;
-            if dyn_token.is_some() {
+            if let Some(dyn_token) = dyn_token {
+                let dyn_span = dyn_token.span;
                 let star_token: Option<Token![*]> = input.parse()?;
-                let bounds = TypeTraitObject::parse_bounds(input, allow_plus)?;
+                let bounds = TypeTraitObject::parse_bounds(dyn_span, input, allow_plus)?;
                 return Ok(if star_token.is_some() {
                     Type::Verbatim(verbatim::between(begin, input))
                 } else {
-                    Type::TraitObject(TypeTraitObject { dyn_token, bounds })
+                    Type::TraitObject(TypeTraitObject {
+                        dyn_token: Some(dyn_token),
+                        bounds,
+                    })
                 });
             }
 
@@ -896,15 +900,6 @@ pub mod parsing {
         }
     }
 
-    fn at_least_one_type(bounds: &Punctuated<TypeParamBound, Token![+]>) -> bool {
-        for bound in bounds {
-            if let TypeParamBound::Trait(_) = *bound {
-                return true;
-            }
-        }
-        false
-    }
-
     impl TypeTraitObject {
         #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
         pub fn without_plus(input: ParseStream) -> Result<Self> {
@@ -914,35 +909,38 @@ pub mod parsing {
 
         // Only allow multiple trait references if allow_plus is true.
         pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> {
-            Ok(TypeTraitObject {
-                dyn_token: input.parse()?,
-                bounds: Self::parse_bounds(input, allow_plus)?,
-            })
+            let dyn_token: Option<Token![dyn]> = input.parse()?;
+            let dyn_span = match &dyn_token {
+                Some(token) => token.span,
+                None => input.span(),
+            };
+            let bounds = Self::parse_bounds(dyn_span, input, allow_plus)?;
+            Ok(TypeTraitObject { dyn_token, bounds })
         }
 
         fn parse_bounds(
+            dyn_span: Span,
             input: ParseStream,
             allow_plus: bool,
         ) -> Result<Punctuated<TypeParamBound, Token![+]>> {
-            let mut bounds = Punctuated::new();
-            loop {
-                bounds.push_value(input.parse()?);
-                if !(allow_plus && input.peek(Token![+])) {
-                    break;
-                }
-                bounds.push_punct(input.parse()?);
-                if !(input.peek(Ident::peek_any)
-                    || input.peek(Token![::])
-                    || input.peek(Token![?])
-                    || input.peek(Lifetime)
-                    || input.peek(token::Paren))
-                {
-                    break;
+            let bounds = TypeParamBound::parse_multiple(input, allow_plus)?;
+            let mut last_lifetime_span = None;
+            let mut at_least_one_trait = false;
+            for bound in &bounds {
+                match bound {
+                    TypeParamBound::Trait(_) => {
+                        at_least_one_trait = true;
+                        break;
+                    }
+                    TypeParamBound::Lifetime(lifetime) => {
+                        last_lifetime_span = Some(lifetime.ident.span());
+                    }
                 }
             }
             // Just lifetimes like `'a + 'b` is not a TraitObject.
-            if !at_least_one_type(&bounds) {
-                return Err(input.error("expected at least one type"));
+            if !at_least_one_trait {
+                let msg = "at least one trait is required for an object type";
+                return Err(error::new2(dyn_span, last_lifetime_span.unwrap(), msg));
             }
             Ok(bounds)
         }
@@ -964,10 +962,30 @@ pub mod parsing {
         }
 
         pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> {
-            Ok(TypeImplTrait {
-                impl_token: input.parse()?,
-                bounds: TypeTraitObject::parse_bounds(input, allow_plus)?,
-            })
+            let impl_token: Token![impl] = input.parse()?;
+            let bounds = TypeParamBound::parse_multiple(input, allow_plus)?;
+            let mut last_lifetime_span = None;
+            let mut at_least_one_trait = false;
+            for bound in &bounds {
+                match bound {
+                    TypeParamBound::Trait(_) => {
+                        at_least_one_trait = true;
+                        break;
+                    }
+                    TypeParamBound::Lifetime(lifetime) => {
+                        last_lifetime_span = Some(lifetime.ident.span());
+                    }
+                }
+            }
+            if !at_least_one_trait {
+                let msg = "at least one trait must be specified";
+                return Err(error::new2(
+                    impl_token.span,
+                    last_lifetime_span.unwrap(),
+                    msg,
+                ));
+            }
+            Ok(TypeImplTrait { impl_token, bounds })
         }
     }
 
diff --git a/vendor/syn/src/verbatim.rs b/vendor/syn/src/verbatim.rs
index 0686352f7..58cf68d17 100644
--- a/vendor/syn/src/verbatim.rs
+++ b/vendor/syn/src/verbatim.rs
@@ -1,13 +1,31 @@
 use crate::parse::{ParseBuffer, ParseStream};
-use proc_macro2::TokenStream;
+use proc_macro2::{Delimiter, TokenStream};
+use std::cmp::Ordering;
 use std::iter;
 
 pub fn between<'a>(begin: ParseBuffer<'a>, end: ParseStream<'a>) -> TokenStream {
     let end = end.cursor();
     let mut cursor = begin.cursor();
+    assert!(crate::buffer::same_buffer(end, cursor));
+
     let mut tokens = TokenStream::new();
     while cursor != end {
         let (tt, next) = cursor.token_tree().unwrap();
+
+        if crate::buffer::cmp_assuming_same_buffer(end, next) == Ordering::Less {
+            // A syntax node can cross the boundary of a None-delimited group
+            // due to such groups being transparent to the parser in most cases.
+            // Any time this occurs the group is known to be semantically
+            // irrelevant. https://github.com/dtolnay/syn/issues/1235
+            if let Some((inside, _span, after)) = cursor.group(Delimiter::None) {
+                assert!(next == after);
+                cursor = inside;
+                continue;
+            } else {
+                panic!("verbatim end must not be inside a delimited group");
+            }
+        }
+
         tokens.extend(iter::once(tt));
         cursor = next;
     }