Avoid ICE in rustdoc when using Fn bounds

src/librustdoc/clean/auto_trait.rs

@@ -354,9 +354,7 @@ where
  ty_to_bounds
  .into_iter()
  .flat_map(|(ty, mut bounds)| {
- if let Some(data) = ty_to_fn.get(&ty) {
- let (poly_trait, output) =
- (data.0.as_ref().unwrap().clone(), data.1.as_ref().cloned().map(Box::new));
+ if let Some((Some(ref poly_trait), ref output)) = ty_to_fn.get(&ty) {
  let mut new_path = poly_trait.trait_.clone();
  let last_segment = new_path.segments.pop().expect("segments were empty");
 
@@ -374,8 +372,9 @@ where
  GenericArgs::Parenthesized { inputs, output } => (inputs, output),
  };
 
+ let output = output.as_ref().cloned().map(Box::new);
  if old_output.is_some() && old_output != output {
- panic!("Output mismatch for {:?} {:?} {:?}", ty, old_output, data.1);
+ panic!("Output mismatch for {:?} {:?} {:?}", ty, old_output, output);
  }
 
  let new_params = GenericArgs::Parenthesized { inputs: old_input, output };
@@ -385,7 +384,10 @@ where
  .push(PathSegment { name: last_segment.name, args: new_params });
 
  bounds.insert(GenericBound::TraitBound(
- PolyTrait { trait_: new_path, generic_params: poly_trait.generic_params },
+ PolyTrait {
+ trait_: new_path,
+ generic_params: poly_trait.generic_params.clone(),
+ },
  hir::TraitBoundModifier::None,
  ));
  }

src/test/rustdoc/fn-bound.rs

@@ -0,0 +1,17 @@
+use std::iter::Peekable;
+
+pub struct Span<F: Fn(&i32)> {
+ inner: Peekable<ConditionalIterator<F>>,
+}
+
+struct ConditionalIterator<F> {
+ f: F,
+}
+
+impl<F: Fn(&i32)> Iterator for ConditionalIterator<F> {
+ type Item = ();
+
+ fn next(&mut self) -> Option<Self::Item> {
+ todo!()
+ }
+}