Process registered region obligation in resolve_regions_with_wf_tys

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -713,6 +713,10 @@ fn resolve_regions_with_wf_tys<'tcx>(
 
     add_constraints(&infcx, region_bound_pairs);
 
+    infcx.process_registered_region_obligations(
+        outlives_environment.region_bound_pairs(),
+        param_env,
+    );
     let errors = infcx.resolve_regions(&outlives_environment);
 
     debug!(?errors, "errors");

src/test/ui/wf/issue-103573.rs

@@ -0,0 +1,22 @@
+trait TraitA {
+    type TypeA;
+}
+
+trait TraitD {
+    type TypeD;
+}
+
+pub trait TraitB {
+    type TypeB: TraitD;
+
+    fn f(_: &<Self::TypeB as TraitD>::TypeD);
+}
+
+pub trait TraitC<E> {
+    type TypeC<'a>: TraitB;
+
+    fn g<'a>(_: &<<Self::TypeC<'a> as TraitB>::TypeB as TraitA>::TypeA);
+    //~^ ERROR the trait bound `<<Self as TraitC<E>>::TypeC<'a> as TraitB>::TypeB: TraitA` is not satisfied
+}
+
+fn main() {}

src/test/ui/wf/issue-103573.stderr

@@ -0,0 +1,14 @@
+error[E0277]: the trait bound `<<Self as TraitC<E>>::TypeC<'a> as TraitB>::TypeB: TraitA` is not satisfied
+  --> $DIR/issue-103573.rs:18:5
+   |
+LL |     fn g<'a>(_: &<<Self::TypeC<'a> as TraitB>::TypeB as TraitA>::TypeA);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `TraitA` is not implemented for `<<Self as TraitC<E>>::TypeC<'a> as TraitB>::TypeB`
+   |
+help: consider further restricting the associated type
+   |
+LL |     fn g<'a>(_: &<<Self::TypeC<'a> as TraitB>::TypeB as TraitA>::TypeA) where <<Self as TraitC<E>>::TypeC<'a> as TraitB>::TypeB: TraitA;
+   |                                                                         +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.