Auto merge of #51139 - vakaras:issue-50716, r=nikomatsakis

Fix NLL issue 50716 and add a regression test.

Fix for NLL issue #50716.

r? @nikomatsakis

src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr

@@ -24,15 +24,16 @@ LL | |     });
    = note: where '_#1r: '_#0r
 
 error: free region `ReFree(DefId(0/0:6 ~ propagate_approximated_shorter_to_static_no_bound[317d]::supply[0]), BrNamed(crate0:DefIndex(1:16), 'a))` does not outlive free region `ReStatic`
-  --> $DIR/propagate-approximated-shorter-to-static-no-bound.rs:45:5
+  --> $DIR/propagate-approximated-shorter-to-static-no-bound.rs:45:47
    |
-LL | /     establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
+LL |       establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
+   |  _______________________________________________^
 LL | |         //~^ ERROR does not outlive free region
 LL | |
 LL | |         // Only works if 'x: 'y:
 LL | |         demand_y(x, y, x.get()) //~ WARNING not reporting region error due to nll
 LL | |     });
-   | |______^
+   | |_____^
 
 note: No external requirements
   --> $DIR/propagate-approximated-shorter-to-static-no-bound.rs:44:1

src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr

@@ -24,15 +24,16 @@ LL | |     });
    = note: where '_#1r: '_#0r
 
 error: free region `ReFree(DefId(0/0:6 ~ propagate_approximated_shorter_to_static_wrong_bound[317d]::supply[0]), BrNamed(crate0:DefIndex(1:16), 'a))` does not outlive free region `ReStatic`
-  --> $DIR/propagate-approximated-shorter-to-static-wrong-bound.rs:48:5
+  --> $DIR/propagate-approximated-shorter-to-static-wrong-bound.rs:48:47
    |
-LL | /     establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y| {
+LL |       establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y| {
+   |  _______________________________________________^
 LL | |         //~^ ERROR does not outlive free region
 LL | |         // Only works if 'x: 'y:
 LL | |         demand_y(x, y, x.get())
 LL | |         //~^ WARNING not reporting region error due to nll
 LL | |     });
-   | |______^
+   | |_____^
 
 note: No external requirements
   --> $DIR/propagate-approximated-shorter-to-static-wrong-bound.rs:47:1

src/test/ui/nll/issue-50716-1.rs

@@ -0,0 +1,23 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// An additional regression test for the issue #50716 “NLL ignores lifetimes
+// bounds derived from `Sized` requirements” that checks that the fixed compiler
+// accepts this code fragment with both AST and MIR borrow checkers.
+//
+// revisions: ast mir
+//
+// compile-pass
+
+#![cfg_attr(mir, feature(nll))]
+
+struct Qey<Q: ?Sized>(Q);
+
+fn main() {}

src/test/ui/nll/issue-50716.rs

@@ -0,0 +1,28 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// Regression test for the issue #50716: NLL ignores lifetimes bounds
+// derived from `Sized` requirements
+
+#![feature(nll)]
+
+trait A {
+    type X: ?Sized;
+}
+
+fn foo<'a, T: 'static>(s: Box<<&'a T as A>::X>)
+where
+    for<'b> &'b T: A,
+    <&'static T as A>::X: Sized
+{
+    let _x = *s; //~ ERROR free region `'a` does not outlive free region `'static`
+}
+
+fn main() {}

src/test/ui/nll/issue-50716.stderr

@@ -0,0 +1,8 @@
+error: free region `'a` does not outlive free region `'static`
+  --> $DIR/issue-50716.rs:25:14
+   |
+LL |     let _x = *s; //~ ERROR free region `'a` does not outlive free region `'static`
+   |              ^^
+
+error: aborting due to previous error
+