From 0034e6199e1ff234715aea73cdd31c9f149f334e Mon Sep 17 00:00:00 2001
From: Mazdak Farrokhzad <twingoow@gmail.com>
Date: Sun, 15 Dec 2019 00:50:44 +0100
Subject: [PATCH] bindings_after_at: harden tests wrt. promotion

---
 .../borrowck-move-and-move.rs                 |   7 +
 .../borrowck-move-and-move.stderr             |  33 +++-
 .../borrowck-pat-at-and-box.rs                |  11 ++
 .../borrowck-pat-at-and-box.stderr            |  33 ++--
 .../borrowck-pat-by-copy-bindings-in-at.rs    |  12 +-
 .../borrowck-pat-by-move-and-ref.rs           |   2 +-
 .../borrowck-pat-ref-both-sides.rs            |  16 +-
 .../borrowck-pat-ref-mut-and-ref.rs           |  14 ++
 .../borrowck-pat-ref-mut-and-ref.stderr       | 180 +++++++++++-------
 .../borrowck-pat-ref-mut-twice.rs             |  12 ++
 .../borrowck-pat-ref-mut-twice.stderr         | 152 ++++++++-------
 11 files changed, 307 insertions(+), 165 deletions(-)

diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.rs b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.rs
index e18d3bc06a93..ba1c8e132f25 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.rs
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.rs
@@ -6,6 +6,9 @@
 fn main() {
     struct U; // Not copy!
 
+    // Prevent promotion:
+    fn u() -> U { U }
+
     let a @ b = U;
     //~^ ERROR cannot bind by-move with sub-bindings
     //~| ERROR use of moved value
@@ -14,6 +17,10 @@ fn main() {
     //~^ ERROR cannot bind by-move with sub-bindings
     //~| ERROR use of moved value
 
+    let a @ (b, c) = (u(), u());
+    //~^ ERROR cannot bind by-move with sub-bindings
+    //~| ERROR use of moved value
+
     match Ok(U) {
         a @ Ok(b) | a @ Err(b) => {}
         //~^ ERROR cannot bind by-move with sub-bindings
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
index 0b69ff0b8392..f08692264e23 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
@@ -7,31 +7,37 @@ LL | #![feature(bindings_after_at)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-move-and-move.rs:9:9
+  --> $DIR/borrowck-move-and-move.rs:12:9
    |
 LL |     let a @ b = U;
    |         ^^^^^ binds an already bound by-move value by moving it
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-move-and-move.rs:13:9
+  --> $DIR/borrowck-move-and-move.rs:16:9
    |
 LL |     let a @ (b, c) = (U, U);
    |         ^^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-move-and-move.rs:18:9
+  --> $DIR/borrowck-move-and-move.rs:20:9
+   |
+LL |     let a @ (b, c) = (u(), u());
+   |         ^^^^^^^^^^ binds an already bound by-move value by moving it
+
+error[E0007]: cannot bind by-move with sub-bindings
+  --> $DIR/borrowck-move-and-move.rs:25:9
    |
 LL |         a @ Ok(b) | a @ Err(b) => {}
    |         ^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-move-and-move.rs:18:21
+  --> $DIR/borrowck-move-and-move.rs:25:21
    |
 LL |         a @ Ok(b) | a @ Err(b) => {}
    |                     ^^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0382]: use of moved value
-  --> $DIR/borrowck-move-and-move.rs:9:13
+  --> $DIR/borrowck-move-and-move.rs:12:13
    |
 LL |     let a @ b = U;
    |         ----^   - move occurs because value has type `main::U`, which does not implement the `Copy` trait
@@ -40,7 +46,7 @@ LL |     let a @ b = U;
    |         value moved here
 
 error[E0382]: use of moved value
-  --> $DIR/borrowck-move-and-move.rs:13:17
+  --> $DIR/borrowck-move-and-move.rs:16:17
    |
 LL |     let a @ (b, c) = (U, U);
    |         --------^-   ------ move occurs because value has type `(main::U, main::U)`, which does not implement the `Copy` trait
@@ -49,7 +55,16 @@ LL |     let a @ (b, c) = (U, U);
    |         value moved here
 
 error[E0382]: use of moved value
-  --> $DIR/borrowck-move-and-move.rs:18:16
+  --> $DIR/borrowck-move-and-move.rs:20:17
+   |
+LL |     let a @ (b, c) = (u(), u());
+   |         --------^-   ---------- move occurs because value has type `(main::U, main::U)`, which does not implement the `Copy` trait
+   |         |       |
+   |         |       value used here after move
+   |         value moved here
+
+error[E0382]: use of moved value
+  --> $DIR/borrowck-move-and-move.rs:25:16
    |
 LL |     match Ok(U) {
    |           ----- move occurs because value has type `std::result::Result<main::U, main::U>`, which does not implement the `Copy` trait
@@ -60,7 +75,7 @@ LL |         a @ Ok(b) | a @ Err(b) => {}
    |         value moved here
 
 error[E0382]: use of moved value
-  --> $DIR/borrowck-move-and-move.rs:18:29
+  --> $DIR/borrowck-move-and-move.rs:25:29
    |
 LL |     match Ok(U) {
    |           ----- move occurs because value has type `std::result::Result<main::U, main::U>`, which does not implement the `Copy` trait
@@ -70,7 +85,7 @@ LL |         a @ Ok(b) | a @ Err(b) => {}
    |                     |       value used here after move
    |                     value moved here
 
-error: aborting due to 8 previous errors
+error: aborting due to 10 previous errors
 
 Some errors have detailed explanations: E0007, E0382.
 For more information about an error, try `rustc --explain E0007`.
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.rs b/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.rs
index 7a4fe96b2133..cf765f579e00 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.rs
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.rs
@@ -7,6 +7,8 @@
 #[derive(Copy, Clone)]
 struct C;
 
+fn c() -> C { C }
+
 fn main() {
     let a @ box &b = Box::new(&C);
     //~^ ERROR cannot bind by-move with sub-bindings
@@ -21,14 +23,23 @@ fn main() {
     drop(b);
     drop(a);
 
+    let ref a @ box b = Box::new(c()); // OK; the type is `Copy`.
+    drop(b);
+    drop(b);
+    drop(a);
+
     struct NC;
 
+    fn nc() -> NC { NC }
+
     let ref a @ box b = Box::new(NC); //~ ERROR cannot bind by-move and by-ref in the same pattern
 
     let ref a @ box ref b = Box::new(NC); // OK.
     drop(a);
     drop(b);
 
+    let ref a @ box ref mut b = Box::new(nc());
+    //~^ ERROR cannot borrow `a` as mutable because it is also borrowed as immutable
     let ref a @ box ref mut b = Box::new(NC);
     //~^ ERROR cannot borrow `a` as mutable because it is also borrowed as immutable
     let ref a @ box ref mut b = Box::new(NC);
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
index 7bb2379968e5..19cd0b7c1d39 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
@@ -7,19 +7,19 @@ LL | #![feature(bindings_after_at)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-pat-at-and-box.rs:11:9
+  --> $DIR/borrowck-pat-at-and-box.rs:13:9
    |
 LL |     let a @ box &b = Box::new(&C);
    |         ^^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-pat-at-and-box.rs:15:9
+  --> $DIR/borrowck-pat-at-and-box.rs:17:9
    |
 LL |     let a @ box b = Box::new(C);
    |         ^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0009]: cannot bind by-move and by-ref in the same pattern
-  --> $DIR/borrowck-pat-at-and-box.rs:26:21
+  --> $DIR/borrowck-pat-at-and-box.rs:35:21
    |
 LL |     let ref a @ box b = Box::new(NC);
    |         ------------^
@@ -28,7 +28,16 @@ LL |     let ref a @ box b = Box::new(NC);
    |         by-ref pattern here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-at-and-box.rs:32:9
+  --> $DIR/borrowck-pat-at-and-box.rs:41:9
+   |
+LL |     let ref a @ box ref mut b = Box::new(nc());
+   |         -----^^^^^^^---------
+   |         |           |
+   |         |           mutable borrow occurs here
+   |         immutable borrow occurs here
+
+error: cannot borrow `a` as mutable because it is also borrowed as immutable
+  --> $DIR/borrowck-pat-at-and-box.rs:43:9
    |
 LL |     let ref a @ box ref mut b = Box::new(NC);
    |         -----^^^^^^^---------
@@ -37,7 +46,7 @@ LL |     let ref a @ box ref mut b = Box::new(NC);
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-at-and-box.rs:34:9
+  --> $DIR/borrowck-pat-at-and-box.rs:45:9
    |
 LL |     let ref a @ box ref mut b = Box::new(NC);
    |         -----^^^^^^^---------
@@ -46,7 +55,7 @@ LL |     let ref a @ box ref mut b = Box::new(NC);
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-at-and-box.rs:37:9
+  --> $DIR/borrowck-pat-at-and-box.rs:48:9
    |
 LL |     let ref a @ box ref mut b = Box::new(NC);
    |         -----^^^^^^^---------
@@ -55,7 +64,7 @@ LL |     let ref a @ box ref mut b = Box::new(NC);
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-at-and-box.rs:43:9
+  --> $DIR/borrowck-pat-at-and-box.rs:54:9
    |
 LL |     let ref mut a @ box ref b = Box::new(NC);
    |         ---------^^^^^^^-----
@@ -64,7 +73,7 @@ LL |     let ref mut a @ box ref b = Box::new(NC);
    |         mutable borrow occurs here
 
 error[E0382]: use of moved value
-  --> $DIR/borrowck-pat-at-and-box.rs:11:18
+  --> $DIR/borrowck-pat-at-and-box.rs:13:18
    |
 LL |     let a @ box &b = Box::new(&C);
    |         ---------^   ------------ move occurs because value has type `std::boxed::Box<&C>`, which does not implement the `Copy` trait
@@ -73,7 +82,7 @@ LL |     let a @ box &b = Box::new(&C);
    |         value moved here
 
 error[E0382]: use of moved value
-  --> $DIR/borrowck-pat-at-and-box.rs:15:17
+  --> $DIR/borrowck-pat-at-and-box.rs:17:17
    |
 LL |     let a @ box b = Box::new(C);
    |         --------^   ----------- move occurs because value has type `std::boxed::Box<C>`, which does not implement the `Copy` trait
@@ -82,7 +91,7 @@ LL |     let a @ box b = Box::new(C);
    |         value moved here
 
 error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-at-and-box.rs:37:21
+  --> $DIR/borrowck-pat-at-and-box.rs:48:21
    |
 LL |     let ref a @ box ref mut b = Box::new(NC);
    |         ------------^^^^^^^^^
@@ -94,7 +103,7 @@ LL |     drop(a);
    |          - immutable borrow later used here
 
 error[E0502]: cannot borrow `_` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-at-and-box.rs:43:25
+  --> $DIR/borrowck-pat-at-and-box.rs:54:25
    |
 LL |     let ref mut a @ box ref b = Box::new(NC);
    |         ----------------^^^^^
@@ -105,7 +114,7 @@ LL |     let ref mut a @ box ref b = Box::new(NC);
 LL |     *a = Box::new(NC);
    |     -- mutable borrow later used here
 
-error: aborting due to 11 previous errors
+error: aborting due to 12 previous errors
 
 Some errors have detailed explanations: E0007, E0009, E0382, E0502.
 For more information about an error, try `rustc --explain E0007`.
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-copy-bindings-in-at.rs b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-copy-bindings-in-at.rs
index 1115dd5b5a28..4cdbfd636f35 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-copy-bindings-in-at.rs
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-copy-bindings-in-at.rs
@@ -9,6 +9,8 @@
 #[derive(Copy, Clone)]
 struct C;
 
+fn mk_c() -> C { C }
+
 #[derive(Copy, Clone)]
 struct P<A, B>(A, B);
 
@@ -16,12 +18,12 @@ enum E<A, B> { L(A), R(B) }
 
 fn main() {
     let a @ b @ c @ d = C;
-    let a @ (b, c) = (C, C);
-    let a @ P(b, P(c, d)) = P(C, P(C, C));
+    let a @ (b, c) = (C, mk_c());
+    let a @ P(b, P(c, d)) = P(mk_c(), P(C, C));
     let a @ [b, c] = [C, C];
-    let a @ [b, .., c] = [C, C, C];
+    let a @ [b, .., c] = [C, mk_c(), C];
     let a @ &(b, c) = &(C, C);
-    let a @ &(b, &P(c, d)) = &(C, &P(C, C));
+    let a @ &(b, &P(c, d)) = &(mk_c(), &P(C, C));
 
     use self::E::*;
     match L(C) {
@@ -31,7 +33,7 @@ fn main() {
             drop(a);
         }
     }
-    match R(&L(&C)) {
+    match R(&L(&mk_c())) {
         L(L(&a)) | L(R(&a)) | R(L(&a)) | R(R(&a)) => {
             let a: C = a;
             drop(a);
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.rs b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.rs
index 4b7f61c365e3..5852e3072290 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.rs
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.rs
@@ -4,7 +4,7 @@
 fn main() {
     match Some("hi".to_string()) {
         ref op_string_ref @ Some(s) => {},
-        //~^ ERROR E0009
+        //~^ ERROR cannot bind by-move and by-ref in the same pattern [E0009]
         None => {},
     }
 }
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-both-sides.rs b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-both-sides.rs
index 5fbedd02d25e..3c501ad8f8a5 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-both-sides.rs
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-both-sides.rs
@@ -9,27 +9,35 @@
 fn main() {
     struct U; // Not copy!
 
+    // Promotion:
     let ref a @ ref b = U;
     let _: &U = a;
     let _: &U = b;
 
-    let ref a @ (ref b, [ref c, ref d]) = (U, [U, U]);
+    // Prevent promotion:
+    fn u() -> U { U }
+
+    let ref a @ ref b = u();
+    let _: &U = a;
+    let _: &U = b;
+
+    let ref a @ (ref b, [ref c, ref d]) = (u(), [u(), u()]);
     let _: &(U, [U; 2]) = a;
     let _: &U = b;
     let _: &U = c;
     let _: &U = d;
 
-    let a @ (b, [c, d]) = &(U, [U, U]);
+    let a @ (b, [c, d]) = &(u(), [u(), u()]);
     let _: &(U, [U; 2]) = a;
     let _: &U = b;
     let _: &U = c;
     let _: &U = d;
 
-    let ref a @ &ref b = &U;
+    let ref a @ &ref b = &u();
     let _: &&U = a;
     let _: &U = b;
 
-    match Ok(U) {
+    match Ok(u()) {
         ref a @ Ok(ref b) | ref a @ Err(ref b) => {
             let _: &Result<U, U> = a;
             let _: &U = b;
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.rs b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.rs
index 35dddfdbb1fb..54b4e1cae85c 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.rs
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.rs
@@ -19,6 +19,9 @@ fn main() {
 
     struct U;
 
+    // Prevent promotion:
+    fn u() -> U { U }
+
     let ref a @ ref mut b = U;
     //~^ ERROR cannot borrow `a` as mutable because it is also borrowed as immutable
     let ref mut a @ ref b = U;
@@ -28,6 +31,17 @@ fn main() {
     let ref mut a @ (ref b, ref c) = (U, U);
     //~^ ERROR cannot borrow `a` as immutable because it is also borrowed as mutable
 
+    let ref mut a @ ref b = u();
+    //~^ ERROR cannot borrow `a` as immutable because it is also borrowed as mutable
+    //~| ERROR cannot borrow `_` as immutable because it is also borrowed as mutable
+    *a = u();
+    drop(b);
+    let ref a @ ref mut b = u();
+    //~^ ERROR cannot borrow `a` as mutable because it is also borrowed as immutable
+    //~| ERROR cannot borrow `_` as mutable because it is also borrowed as immutable
+    *b = u();
+    drop(a);
+
     let ref mut a @ ref b = U;
     //~^ ERROR cannot borrow `a` as immutable because it is also borrowed as mutable
     *a = U;
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr
index 7059f3c7caa8..04944c1d528d 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-and-ref.stderr
@@ -16,7 +16,7 @@ LL |         ref mut z @ &mut Some(ref a) => {
    |         mutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:22:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:25:9
    |
 LL |     let ref a @ ref mut b = U;
    |         -----^^^---------
@@ -25,7 +25,7 @@ LL |     let ref a @ ref mut b = U;
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:24:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:27:9
    |
 LL |     let ref mut a @ ref b = U;
    |         ---------^^^-----
@@ -34,7 +34,7 @@ LL |     let ref mut a @ ref b = U;
    |         mutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:26:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:29:9
    |
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         -----^^^^---------^^---------^
@@ -44,7 +44,7 @@ LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:28:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:31:9
    |
 LL |     let ref mut a @ (ref b, ref c) = (U, U);
    |         ---------^^^^-----^^-----^
@@ -54,7 +54,25 @@ LL |     let ref mut a @ (ref b, ref c) = (U, U);
    |         mutable borrow occurs here
 
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:31:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:34:9
+   |
+LL |     let ref mut a @ ref b = u();
+   |         ---------^^^-----
+   |         |           |
+   |         |           immutable borrow occurs here
+   |         mutable borrow occurs here
+
+error: cannot borrow `a` as mutable because it is also borrowed as immutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:39:9
+   |
+LL |     let ref a @ ref mut b = u();
+   |         -----^^^---------
+   |         |       |
+   |         |       mutable borrow occurs here
+   |         immutable borrow occurs here
+
+error: cannot borrow `a` as immutable because it is also borrowed as mutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:45:9
    |
 LL |     let ref mut a @ ref b = U;
    |         ---------^^^-----
@@ -63,7 +81,7 @@ LL |     let ref mut a @ ref b = U;
    |         mutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:35:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:49:9
    |
 LL |     let ref a @ ref mut b = U;
    |         -----^^^---------
@@ -72,7 +90,7 @@ LL |     let ref a @ ref mut b = U;
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:41:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:55:9
    |
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) => {
    |         ---------^^^^^^-----^
@@ -81,7 +99,7 @@ LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) => {
    |         mutable borrow occurs here
 
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:41:33
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:55:33
    |
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) => {
    |                                 ---------^^^^^^^-----^
@@ -90,7 +108,7 @@ LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) => {
    |                                 mutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:50:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:64:9
    |
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |         -----^^^^^^---------^
@@ -99,7 +117,7 @@ LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:50:33
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:64:33
    |
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |                                 -----^^^^^^^---------^
@@ -107,46 +125,10 @@ LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |                                 |           mutable borrow occurs here
    |                                 immutable borrow occurs here
 
-error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:61:9
-   |
-LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false } => {}
-   |         -----^^^^^^---------^
-   |         |          |
-   |         |          mutable borrow occurs here
-   |         immutable borrow occurs here
-
-error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:61:33
-   |
-LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false } => {}
-   |                                 -----^^^^^^^---------^
-   |                                 |           |
-   |                                 |           mutable borrow occurs here
-   |                                 immutable borrow occurs here
-
-error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:68:9
-   |
-LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); false } => {}
-   |         ---------^^^^^^-----^
-   |         |              |
-   |         |              immutable borrow occurs here
-   |         mutable borrow occurs here
-
-error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:68:33
-   |
-LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); false } => {}
-   |                                 ---------^^^^^^^-----^
-   |                                 |               |
-   |                                 |               immutable borrow occurs here
-   |                                 mutable borrow occurs here
-
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:75:9
    |
-LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false } => {}
+LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false } => {}
    |         -----^^^^^^---------^
    |         |          |
    |         |          mutable borrow occurs here
@@ -155,7 +137,7 @@ LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:75:33
    |
-LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false } => {}
+LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false } => {}
    |                                 -----^^^^^^^---------^
    |                                 |           |
    |                                 |           mutable borrow occurs here
@@ -164,7 +146,7 @@ LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:82:9
    |
-LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false } => {}
+LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); false } => {}
    |         ---------^^^^^^-----^
    |         |              |
    |         |              immutable borrow occurs here
@@ -173,7 +155,7 @@ LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:82:33
    |
-LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false } => {}
+LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); false } => {}
    |                                 ---------^^^^^^^-----^
    |                                 |               |
    |                                 |               immutable borrow occurs here
@@ -182,15 +164,41 @@ LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
   --> $DIR/borrowck-pat-ref-mut-and-ref.rs:89:9
    |
-LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
-   |         -----^^^^---------^^---------^
-   |         |        |          |
-   |         |        |          mutable borrow occurs here
-   |         |        mutable borrow occurs here
+LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false } => {}
+   |         -----^^^^^^---------^
+   |         |          |
+   |         |          mutable borrow occurs here
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:94:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:89:33
+   |
+LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false } => {}
+   |                                 -----^^^^^^^---------^
+   |                                 |           |
+   |                                 |           mutable borrow occurs here
+   |                                 immutable borrow occurs here
+
+error: cannot borrow `a` as immutable because it is also borrowed as mutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:96:9
+   |
+LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false } => {}
+   |         ---------^^^^^^-----^
+   |         |              |
+   |         |              immutable borrow occurs here
+   |         mutable borrow occurs here
+
+error: cannot borrow `a` as immutable because it is also borrowed as mutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:96:33
+   |
+LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false } => {}
+   |                                 ---------^^^^^^^-----^
+   |                                 |               |
+   |                                 |               immutable borrow occurs here
+   |                                 mutable borrow occurs here
+
+error: cannot borrow `a` as mutable because it is also borrowed as immutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:103:9
    |
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         -----^^^^---------^^---------^
@@ -200,7 +208,17 @@ LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:101:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:108:9
+   |
+LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
+   |         -----^^^^---------^^---------^
+   |         |        |          |
+   |         |        |          mutable borrow occurs here
+   |         |        mutable borrow occurs here
+   |         immutable borrow occurs here
+
+error: cannot borrow `a` as mutable because it is also borrowed as immutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:115:9
    |
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         -----^^^^---------^^---------^
@@ -210,7 +228,7 @@ LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         immutable borrow occurs here
 
 error: cannot borrow `a` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:106:9
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:120:9
    |
 LL |     let ref mut a @ (ref b, ref c) = (U, U);
    |         ---------^^^^-----^^-----^
@@ -231,8 +249,32 @@ LL |         ref mut z @ &mut Some(ref a) => {
 LL |             **z = None;
    |             ---------- mutable borrow later used here
 
+error[E0502]: cannot borrow `_` as immutable because it is also borrowed as mutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:34:21
+   |
+LL |     let ref mut a @ ref b = u();
+   |         ------------^^^^^
+   |         |           |
+   |         |           immutable borrow occurs here
+   |         mutable borrow occurs here
+...
+LL |     *a = u();
+   |     -------- mutable borrow later used here
+
 error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:50:20
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:39:17
+   |
+LL |     let ref a @ ref mut b = u();
+   |         --------^^^^^^^^^
+   |         |       |
+   |         |       mutable borrow occurs here
+   |         immutable borrow occurs here
+...
+LL |     drop(a);
+   |          - immutable borrow later used here
+
+error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:64:20
    |
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |         -----------^^^^^^^^^-
@@ -244,7 +286,7 @@ LL |             drop(a);
    |                  - immutable borrow later used here
 
 error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:50:45
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:64:45
    |
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) => {
    |                                 ------------^^^^^^^^^-
@@ -256,7 +298,7 @@ LL |             drop(a);
    |                  - immutable borrow later used here
 
 error[E0594]: cannot assign to `*b`, as it is immutable for the pattern guard
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:61:61
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:75:61
    |
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false } => {}
    |                                                             ^^^^^^ cannot assign
@@ -264,7 +306,7 @@ LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { *b = U; false }
    = note: variables bound in patterns are immutable until the end of the pattern guard
 
 error[E0594]: cannot assign to `*a`, as it is immutable for the pattern guard
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:68:61
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:82:61
    |
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); false } => {}
    |                                                             ^^^^^^^^^^^ cannot assign
@@ -272,7 +314,7 @@ LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { *a = Err(U); fa
    = note: variables bound in patterns are immutable until the end of the pattern guard
 
 error[E0507]: cannot move out of `b` in pattern guard
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:75:66
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:89:66
    |
 LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false } => {}
    |                                                                  ^ move occurs because `b` has type `&mut main::U`, which does not implement the `Copy` trait
@@ -280,7 +322,7 @@ LL |         ref a @ Ok(ref mut b) | ref a @ Err(ref mut b) if { drop(b); false
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
 error[E0507]: cannot move out of `a` in pattern guard
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:82:66
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:96:66
    |
 LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false } => {}
    |                                                                  ^ move occurs because `a` has type `&mut std::result::Result<main::U, main::U>`, which does not implement the `Copy` trait
@@ -288,7 +330,7 @@ LL |         ref mut a @ Ok(ref b) | ref mut a @ Err(ref b) if { drop(a); false
    = note: variables bound in patterns cannot be moved from until after the end of the pattern guard
 
 error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:94:18
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:108:18
    |
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         ---------^^^^^^^^^------------
@@ -300,7 +342,7 @@ LL |     drop(a);
    |          - immutable borrow later used here
 
 error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:94:29
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:108:29
    |
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         --------------------^^^^^^^^^-
@@ -312,7 +354,7 @@ LL |     drop(a);
    |          - immutable borrow later used here
 
 error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:101:18
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:115:18
    |
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         ---------^^^^^^^^^------------
@@ -324,7 +366,7 @@ LL |     drop(a);
    |          - immutable borrow later used here
 
 error[E0502]: cannot borrow `_` as mutable because it is also borrowed as immutable
-  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:101:29
+  --> $DIR/borrowck-pat-ref-mut-and-ref.rs:115:29
    |
 LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
    |         --------------------^^^^^^^^^-
@@ -335,7 +377,7 @@ LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
 LL |     drop(a);
    |          - immutable borrow later used here
 
-error: aborting due to 34 previous errors
+error: aborting due to 38 previous errors
 
 Some errors have detailed explanations: E0502, E0507, E0594.
 For more information about an error, try `rustc --explain E0502`.
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.rs b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.rs
index f76d9ce73cf2..487ac4b852b6 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.rs
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.rs
@@ -6,6 +6,8 @@
 fn main() {
     struct U;
 
+    fn u() -> U { U }
+
     let ref mut a @ ref mut b = U;
     //~^ ERROR cannot borrow `a` as mutable more than once at a time
     //~| ERROR cannot borrow `_` as mutable more than once at a time
@@ -34,6 +36,16 @@ fn main() {
         ]
     ) = (U, [U, U, U]);
 
+    let ref mut a @ (
+        //~^ ERROR cannot borrow `a` as mutable more than once at a time
+            ref mut b,
+            [
+                ref mut c,
+                ref mut d,
+                ref e,
+            ]
+        ) = (u(), [u(), u(), u()]);
+
     let a @ (ref mut b, ref mut c) = (U, U);
     //~^ ERROR cannot bind by-move with sub-bindings
     //~| ERROR borrow of moved value
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
index e8176342a0c4..011e18be8b29 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
@@ -7,7 +7,7 @@ LL | #![feature(bindings_after_at)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:9:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:11:9
    |
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
@@ -16,7 +16,7 @@ LL |     let ref mut a @ ref mut b = U;
    |         first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:13:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:15:9
    |
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
@@ -25,7 +25,7 @@ LL |     let ref mut a @ ref mut b = U;
    |         first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:16:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:18:9
    |
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
@@ -34,7 +34,7 @@ LL |     let ref mut a @ ref mut b = U;
    |         first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:19:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:21:9
    |
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
@@ -43,7 +43,7 @@ LL |     let ref mut a @ ref mut b = U;
    |         first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:23:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:25:9
    |
 LL |     let ref mut a @ ref mut b = U;
    |         ---------^^^---------
@@ -52,7 +52,7 @@ LL |     let ref mut a @ ref mut b = U;
    |         first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:27:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:29:9
    |
 LL |       let ref mut a @ (
    |           ^--------
@@ -73,32 +73,54 @@ LL | |         ]
 LL | |     ) = (U, [U, U, U]);
    | |_____^
 
+error: cannot borrow `a` as mutable more than once at a time
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:39:9
+   |
+LL |       let ref mut a @ (
+   |           ^--------
+   |           |
+   |  _________first mutable borrow occurs here
+   | |
+LL | |
+LL | |             ref mut b,
+   | |             --------- another mutable borrow occurs here
+LL | |             [
+LL | |                 ref mut c,
+   | |                 --------- another mutable borrow occurs here
+LL | |                 ref mut d,
+   | |                 --------- another mutable borrow occurs here
+LL | |                 ref e,
+   | |                 ----- also borrowed as immutable here
+LL | |             ]
+LL | |         ) = (u(), [u(), u(), u()]);
+   | |_________^
+
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:37:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:49:9
    |
 LL |     let a @ (ref mut b, ref mut c) = (U, U);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:41:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:53:9
    |
 LL |     let a @ (b, [c, d]) = &mut val; // Same as ^--
    |         ^^^^^^^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:45:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:57:9
    |
 LL |     let a @ &mut ref mut b = &mut U;
    |         ^^^^^^^^^^^^^^^^^^ binds an already bound by-move value by moving it
 
 error[E0007]: cannot bind by-move with sub-bindings
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:48:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:60:9
    |
 LL |     let a @ &mut (ref mut b, ref mut c) = &mut (U, U);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ binds an already bound by-move value by moving it
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:53:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:65:9
    |
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         ---------^^^^^^---------^
@@ -107,7 +129,7 @@ LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:53:37
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:65:37
    |
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     ---------^^^^^^^---------^
@@ -116,7 +138,7 @@ LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:59:9
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:71:9
    |
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         ---------^^^^^^---------^
@@ -125,25 +147,7 @@ LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         first mutable borrow occurs here
 
 error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:59:37
-   |
-LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
-   |                                     ---------^^^^^^^---------^
-   |                                     |               |
-   |                                     |               another mutable borrow occurs here
-   |                                     first mutable borrow occurs here
-
-error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:66:9
-   |
-LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
-   |         ---------^^^^^^---------^
-   |         |              |
-   |         |              another mutable borrow occurs here
-   |         first mutable borrow occurs here
-
-error: cannot borrow `a` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:66:37
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:71:37
    |
 LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     ---------^^^^^^^---------^
@@ -169,8 +173,26 @@ LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     |               another mutable borrow occurs here
    |                                     first mutable borrow occurs here
 
+error: cannot borrow `a` as mutable more than once at a time
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:90:9
+   |
+LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
+   |         ---------^^^^^^---------^
+   |         |              |
+   |         |              another mutable borrow occurs here
+   |         first mutable borrow occurs here
+
+error: cannot borrow `a` as mutable more than once at a time
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:90:37
+   |
+LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
+   |                                     ---------^^^^^^^---------^
+   |                                     |               |
+   |                                     |               another mutable borrow occurs here
+   |                                     first mutable borrow occurs here
+
 error[E0499]: cannot borrow `_` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:9:21
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:11:21
    |
 LL |     let ref mut a @ ref mut b = U;
    |         ------------^^^^^^^^^
@@ -182,7 +204,7 @@ LL |     drop(a);
    |          - first borrow later used here
 
 error[E0499]: cannot borrow `_` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:19:21
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:21:21
    |
 LL |     let ref mut a @ ref mut b = U;
    |         ------------^^^^^^^^^
@@ -194,7 +216,7 @@ LL |     *a = U;
    |     ------ first borrow later used here
 
 error[E0382]: borrow of moved value
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:37:25
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:49:25
    |
 LL |     let a @ (ref mut b, ref mut c) = (U, U);
    |         ----------------^^^^^^^^^-   ------ move occurs because value has type `(main::U, main::U)`, which does not implement the `Copy` trait
@@ -203,7 +225,7 @@ LL |     let a @ (ref mut b, ref mut c) = (U, U);
    |         value moved here
 
 error[E0382]: borrow of moved value
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:41:21
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:53:21
    |
 LL |     let a @ (b, [c, d]) = &mut val; // Same as ^--
    |         ------------^--   -------- move occurs because value has type `&mut (main::U, [main::U; 2])`, which does not implement the `Copy` trait
@@ -212,7 +234,7 @@ LL |     let a @ (b, [c, d]) = &mut val; // Same as ^--
    |         value moved here
 
 error[E0382]: borrow of moved value
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:45:18
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:57:18
    |
 LL |     let a @ &mut ref mut b = &mut U;
    |         ---------^^^^^^^^^   ------ move occurs because value has type `&mut main::U`, which does not implement the `Copy` trait
@@ -221,7 +243,7 @@ LL |     let a @ &mut ref mut b = &mut U;
    |         value moved here
 
 error[E0382]: borrow of moved value
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:48:30
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:60:30
    |
 LL |     let a @ &mut (ref mut b, ref mut c) = &mut (U, U);
    |         ---------------------^^^^^^^^^-   ----------- move occurs because value has type `&mut (main::U, main::U)`, which does not implement the `Copy` trait
@@ -229,30 +251,6 @@ LL |     let a @ &mut (ref mut b, ref mut c) = &mut (U, U);
    |         |                    value borrowed here after move
    |         value moved here
 
-error[E0499]: cannot borrow `_` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:66:24
-   |
-LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
-   |         ---------------^^^^^^^^^-
-   |         |              |
-   |         |              second mutable borrow occurs here
-   |         first mutable borrow occurs here
-...
-LL |             *a = Err(U);
-   |             ----------- first borrow later used here
-
-error[E0499]: cannot borrow `_` as mutable more than once at a time
-  --> $DIR/borrowck-pat-ref-mut-twice.rs:66:53
-   |
-LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
-   |                                     ----------------^^^^^^^^^-
-   |                                     |               |
-   |                                     |               second mutable borrow occurs here
-   |                                     first mutable borrow occurs here
-...
-LL |             *a = Err(U);
-   |             ----------- first borrow later used here
-
 error[E0499]: cannot borrow `_` as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:78:24
    |
@@ -262,8 +260,8 @@ LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |         |              second mutable borrow occurs here
    |         first mutable borrow occurs here
 ...
-LL |             drop(a);
-   |                  - first borrow later used here
+LL |             *a = Err(U);
+   |             ----------- first borrow later used here
 
 error[E0499]: cannot borrow `_` as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:78:53
@@ -274,10 +272,34 @@ LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
    |                                     |               second mutable borrow occurs here
    |                                     first mutable borrow occurs here
 ...
+LL |             *a = Err(U);
+   |             ----------- first borrow later used here
+
+error[E0499]: cannot borrow `_` as mutable more than once at a time
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:90:24
+   |
+LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
+   |         ---------------^^^^^^^^^-
+   |         |              |
+   |         |              second mutable borrow occurs here
+   |         first mutable borrow occurs here
+...
 LL |             drop(a);
    |                  - first borrow later used here
 
-error: aborting due to 28 previous errors
+error[E0499]: cannot borrow `_` as mutable more than once at a time
+  --> $DIR/borrowck-pat-ref-mut-twice.rs:90:53
+   |
+LL |         ref mut a @ Ok(ref mut b) | ref mut a @ Err(ref mut b) => {
+   |                                     ----------------^^^^^^^^^-
+   |                                     |               |
+   |                                     |               second mutable borrow occurs here
+   |                                     first mutable borrow occurs here
+...
+LL |             drop(a);
+   |                  - first borrow later used here
+
+error: aborting due to 29 previous errors
 
 Some errors have detailed explanations: E0007, E0382, E0499.
 For more information about an error, try `rustc --explain E0007`.