From 86040b7505c0e138ef6b476614a03e35c0706c05 Mon Sep 17 00:00:00 2001
From: Alan Donovan <adonovan@google.com>
Date: Mon, 12 Jan 2015 12:48:42 -0500
Subject: [PATCH] go/types: close scope for each "select" case after its body

Classic Go pitfall: "defer" in a loop does not do what you might expect.

+ test case

Fixes issue 9570
Fixes issue 9569

Change-Id: Iec05420872ef71190083a7192f76c92f54f4a2a1
Reviewed-on: https://go-review.googlesource.com/2655
Reviewed-by: Robert Griesemer <gri@golang.org>
---
 go/types/stmt.go            |  2 +-
 go/types/testdata/stmt0.src | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/go/types/stmt.go b/go/types/stmt.go
index 42580bdd..fa60f64d 100644
--- a/go/types/stmt.go
+++ b/go/types/stmt.go
@@ -569,11 +569,11 @@ func (check *Checker) stmt(ctxt stmtContext, s ast.Stmt) {
 			}
 
 			check.openScope(s, "case")
-			defer check.closeScope()
 			if clause.Comm != nil {
 				check.stmt(inner, clause.Comm)
 			}
 			check.stmtList(inner, clause.Body)
+			check.closeScope()
 		}
 
 	case *ast.ForStmt:
diff --git a/go/types/testdata/stmt0.src b/go/types/testdata/stmt0.src
index 646c4189..4c840367 100644
--- a/go/types/testdata/stmt0.src
+++ b/go/types/testdata/stmt0.src
@@ -215,6 +215,17 @@ func selects() {
 	case x /* ERROR send or receive */ :
 	case a /* ERROR send or receive */ := ch:
 	}
+
+	// test for issue 9570: ch2 in second case falsely resolved to
+	// ch2 declared in body of first case
+	ch1 := make(chan int)
+	ch2 := make(chan int)
+	select {
+	case <-ch1:
+		var ch2 /* ERROR ch2 declared but not used */ chan bool
+	case i := <-ch2:
+		print(i + 1)
+	}
 }
 
 func gos() {