go/types: set type of lhs ident in type switch guards

(bug fix)

R=adonovan
CC=golang-dev
https://golang.org/cl/7098059

diff --git a/src/pkg/go/types/stmt.go b/src/pkg/go/types/stmt.go
index f1d6704110574bf6ff142627819ae6fdc87d59bd..11a2e7196dc5dae73aaeb8f2c0a540161e44f972 100644 (file)
--- a/src/pkg/go/types/stmt.go
+++ b/src/pkg/go/types/stmt.go
@@ -610,10 +610,10 @@ func (check *checker) stmt(s ast.Stmt) {
                }
 
                // There is only one object (lhs) associated with a lhs identifier, but that object
-               // assumes different types for different clauses. Set it to nil when we are done so
-               // that the type cannot be used by mistake.
+               // assumes different types for different clauses. Set it back to the type of the
+               // TypeSwitchGuard expression so that that variable always has a valid type.
                if lhs != nil {
-                       lhs.Type = nil
+                       lhs.Type = x.typ
                }
 
        case *ast.SelectStmt: