Add a test for returning inside a while loop

src/test/ui/break-while-condition.rs

@@ -11,7 +11,29 @@
 #![feature(never_type)]
 
 fn main() {
+    // The `if false` expressions are simply to
+    // make sure we don't avoid checking everything
+    // simply because a few expressions are unreachable.
+
+    if false {
         let _: ! = { //~ ERROR mismatched types
             'a: while break 'a {};
         };
+    }
+
+    if false {
+        let _: ! = { //~ ERROR mismatched types
+            while false {
+                break
+            }
+        };
+    }
+
+    if false {
+        let _: ! = { //~ ERROR mismatched types
+            while false {
+                return
+            }
+        };
+    }
 }

src/test/ui/break-while-condition.stderr

@@ -1,15 +1,43 @@
 error[E0308]: mismatched types
-  --> $DIR/break-while-condition.rs:14:16
+  --> $DIR/break-while-condition.rs:19:20
    |
 LL |           let _: ! = { //~ ERROR mismatched types
-   |  ________________^
+   |  ____________________^
 LL | |             'a: while break 'a {};
 LL | |         };
-   | |_____^ expected !, found ()
+   | |_________^ expected !, found ()
    |
    = note: expected type `!`
               found type `()`
 
-error: aborting due to previous error
+error[E0308]: mismatched types
+  --> $DIR/break-while-condition.rs:26:13
+   |
+LL |   fn main() {
+   |             - expected `()` because of default return type
+...
+LL | /             while false {
+LL | |                 break
+LL | |             }
+   | |_____________^ expected !, found ()
+   |
+   = note: expected type `!`
+              found type `()`
+
+error[E0308]: mismatched types
+  --> $DIR/break-while-condition.rs:34:13
+   |
+LL |   fn main() {
+   |             - expected `()` because of default return type
+...
+LL | /             while false {
+LL | |                 return
+LL | |             }
+   | |_____________^ expected !, found ()
+   |
+   = note: expected type `!`
+              found type `()`
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0308`.