Use the correct ParamEnv

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -2219,12 +2219,12 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             return Ok(None);
         }
 
+        let param_env = tcx.param_env(block.owner.to_def_id());
         let cause = ObligationCause::misc(span, block.owner.def_id);
         let mut unsatisfied_predicates = Vec::new();
 
         for &(impl_, (assoc_item, def_scope)) in &candidates {
             let infcx = tcx.infer_ctxt().ignoring_regions().build();
-            let param_env = tcx.param_env(impl_);
 
             let impl_ty = tcx.type_of(impl_);
             let impl_substs = self.fresh_item_substs(impl_, &infcx);

tests/ui/associated-inherent-types/dispatch-on-self-type-0.rs

@@ -33,3 +33,9 @@ fn main() {
     let _: Choose<NonCopy>::Result = ();
     let _: Choose<&str>::Result = vec!["..."];
 }
+
+// Test if we use the correct `ParamEnv` when proving obligations.
+
+pub fn parameterized<T: Copy>(x: T) {
+    let _: Choose<T>::Result = vec![x];
+}

tests/ui/associated-inherent-types/not-found-unsatisfied-bounds-0.stderr

@@ -1,5 +1,5 @@
 error: the associated type `Yield` exists for `Container<[u8]>`, but its trait bounds were not satisfied
-  --> $DIR/not-found-unsatisfied-bounds.rs:19:29
+  --> $DIR/not-found-unsatisfied-bounds-0.rs:19:29
    |
 LL | struct Container<T: ?Sized>(T);
    | --------------------------- associated item `Yield` not found for this struct
@@ -11,7 +11,7 @@ LL |     let _: Container<[u8]>::Yield = 1;
            `[u8]: Sized`
 
 error: the associated type `Combination` exists for `Duple<String, Rc<str>>`, but its trait bounds were not satisfied
-  --> $DIR/not-found-unsatisfied-bounds.rs:20:45
+  --> $DIR/not-found-unsatisfied-bounds-0.rs:20:45
    |
 LL | struct Duple<T, U>(T, U);
    | ------------------ associated item `Combination` not found for this struct

tests/ui/associated-inherent-types/not-found-unsatisfied-bounds-1.rs

@@ -0,0 +1,18 @@
+// fail-check
+
+#![feature(inherent_associated_types)]
+#![allow(incomplete_features)]
+
+// Test if we use the correct `ParamEnv` when proving obligations.
+
+fn parameterized<T>() {
+    let _: Container<T>::Proj = String::new(); //~ ERROR the associated type `Proj` exists for `Container<T>`, but its trait bounds were not satisfied
+}
+
+struct Container<T>(T);
+
+impl<T: Clone> Container<T> {
+    type Proj = String;
+}
+
+fn main() {}

tests/ui/associated-inherent-types/not-found-unsatisfied-bounds-1.stderr

@@ -0,0 +1,14 @@
+error: the associated type `Proj` exists for `Container<T>`, but its trait bounds were not satisfied
+  --> $DIR/not-found-unsatisfied-bounds-1.rs:9:26
+   |
+LL |     let _: Container<T>::Proj = String::new();
+   |                          ^^^^ associated type cannot be referenced on `Container<T>` due to unsatisfied trait bounds
+...
+LL | struct Container<T>(T);
+   | ------------------- associated item `Proj` not found for this struct
+   |
+   = note: the following trait bounds were not satisfied:
+           `T: Clone`
+
+error: aborting due to previous error
+