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fix: panicking_unwrap FP on field access with implicit deref

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(cherry picked from commit c905503474)
This commit is contained in:
Linshu Yang 2025-12-05 18:18:58 +00:00 • committed by Josh Stone
parent feb759bb79
commit 9c13ace16d
2 changed files with 26 additions and 2 deletions
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9
src/tools/clippy/clippy_lints/src/unwrap.rs
View file

@ -180,14 +180,19 @@ impl Local {
field_indices,
..
} => {
let field_projections = place
.projections
.iter()
.filter(|proj| matches!(proj.kind, ProjectionKind::Field(_, _)))
.collect::<Vec<_>>();
is_potentially_local_place(*local_id, place)
// If there were projections other than field projections, err on the side of caution and say that they
// _might_ be mutating something.
//
// The reason we use `<=` and not `==` is that a mutation of `struct` or `struct.field1` should count as
// mutation of the child fields such as `struct.field1.field2`
&& place.projections.len() <= field_indices.len()
&& iter::zip(&place.projections, field_indices.iter().copied().rev()).all(|(proj, field_idx)| {
&& field_projections.len() <= field_indices.len()
&& iter::zip(&field_projections, field_indices.iter().copied().rev()).all(|(proj, field_idx)| {
match proj.kind {
ProjectionKind::Field(f_idx, _) => f_idx == field_idx,
// If this is a projection we don't expect, it _might_ be mutating something

19
src/tools/clippy/tests/ui/checked_unwrap/simple_conditionals.rs
View file

@ -472,3 +472,22 @@ fn issue15321() {
//~^ unnecessary_unwrap
}
}
mod issue16188 {
struct Foo {
value: Option<i32>,
}
impl Foo {
pub fn bar(&mut self) {
let print_value = |v: i32| {
println!("{}", v);
};
if self.value.is_none() {
self.value = Some(10);
print_value(self.value.unwrap());
}
}
}
}