4 files changed, 49 insertions, 15 deletions
diff --git a/tests/mir-opt/instsimplify/casts.redundant.InstSimplify.diff b/tests/mir-opt/instsimplify/casts.redundant.InstSimplify.diff
index 1c417d4346d..9e1bce1ee20 100644
--- a/tests/mir-opt/instsimplify/casts.redundant.InstSimplify.diff
+++ b/tests/mir-opt/instsimplify/casts.redundant.InstSimplify.diff
@@ -6,22 +6,27 @@
       let mut _0: *const &u8;
       let mut _2: *const &u8;
       let mut _3: *const &u8;
+      let mut _4: *const &u8;
       scope 1 (inlined generic_cast::<&u8, &u8>) {
-          debug x => _3;
-          let mut _4: *const &u8;
+          debug x => _4;
+          let mut _5: *const &u8;
       }
   
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
-          _3 = _1;
           StorageLive(_4);
-          _4 = _3;
--         _2 = move _4 as *const &u8 (PtrToPtr);
-+         _2 = move _4;
+          _4 = _1;
+          StorageLive(_5);
+          _5 = _4;
+-         _3 = move _5 as *const &u8 (PtrToPtr);
++         _3 = move _5;
+          StorageDead(_5);
           StorageDead(_4);
-          StorageDead(_3);
+-         _2 = move _3 as *const &u8 (PtrToPtr);
++         _2 = move _3;
           _0 = _2;
+          StorageDead(_3);
           StorageDead(_2);
           return;
       }
diff --git a/tests/mir-opt/instsimplify/casts.roundtrip.InstSimplify.diff b/tests/mir-opt/instsimplify/casts.roundtrip.InstSimplify.diff
index 1ae9d45e66c..a6d68cd4e4b 100644
--- a/tests/mir-opt/instsimplify/casts.roundtrip.InstSimplify.diff
+++ b/tests/mir-opt/instsimplify/casts.roundtrip.InstSimplify.diff
@@ -4,16 +4,21 @@
   fn roundtrip(_1: *const u8) -> *const u8 {
       debug x => _1;
       let mut _0: *const u8;
-      let mut _2: *mut u8;
-      let mut _3: *const u8;
+      let mut _2: *const u8;
+      let mut _3: *mut u8;
+      let mut _4: *const u8;
   
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
-          _3 = _1;
-          _2 = move _3 as *mut u8 (PtrToPtr);
-          _0 = move _2 as *const u8 (PointerCoercion(MutToConstPointer));
+          StorageLive(_4);
+          _4 = _1;
+          _3 = move _4 as *mut u8 (PtrToPtr);
+          _2 = move _3 as *const u8 (PointerCoercion(MutToConstPointer));
+          StorageDead(_4);
           StorageDead(_3);
+-         _0 = move _2 as *const u8 (PtrToPtr);
++         _0 = move _2;
           StorageDead(_2);
           return;
       }
diff --git a/tests/mir-opt/instsimplify/casts.rs b/tests/mir-opt/instsimplify/casts.rs
index 18bab524c64..86f9b34ea04 100644
--- a/tests/mir-opt/instsimplify/casts.rs
+++ b/tests/mir-opt/instsimplify/casts.rs
@@ -18,8 +18,8 @@ pub fn redundant<'a, 'b: 'a>(x: *const &'a u8) -> *const &'a u8 {
 // EMIT_MIR casts.roundtrip.InstSimplify.diff
 pub fn roundtrip(x: *const u8) -> *const u8 {
     // CHECK-LABEL: fn roundtrip(
-    // CHECK: _3 = _1;
-    // CHECK: _2 = move _3 as *mut u8 (PtrToPtr);
-    // CHECK: _0 = move _2 as *const u8 (PointerCoercion(MutToConstPointer));
+    // CHECK: _4 = _1;
+    // CHECK: _3 = move _4 as *mut u8 (PtrToPtr);
+    // CHECK: _2 = move _3 as *const u8 (PointerCoercion(MutToConstPointer));
     x as *mut u8 as *const u8
 }
diff --git a/tests/ui/cast/ptr-to-ptr-different-regions.rs b/tests/ui/cast/ptr-to-ptr-different-regions.rs
new file mode 100644
index 00000000000..5592e613ac1
--- /dev/null
+++ b/tests/ui/cast/ptr-to-ptr-different-regions.rs
@@ -0,0 +1,24 @@
+// check-pass
+
+// https://github.com/rust-lang/rust/issues/113257
+
+#![deny(trivial_casts)] // The casts here are not trivial.
+
+struct Foo<'a> { a: &'a () }
+
+fn extend_lifetime_very_very_safely<'a>(v: *const Foo<'a>) -> *const Foo<'static> {
+    // This should pass because raw pointer casts can do anything they want.
+    v as *const Foo<'static>
+}
+
+trait Trait {}
+
+fn assert_static<'a>(ptr: *mut (dyn Trait + 'a)) -> *mut (dyn Trait + 'static) {
+    ptr as _
+}
+
+fn main() {
+    let unit = ();
+    let foo = Foo { a: &unit };
+    let _long: *const Foo<'static> = extend_lifetime_very_very_safely(&foo);
+}