From 4eaf0b7a58d024e7d44f58a26914fb1885fd4dd6 Mon Sep 17 00:00:00 2001
From: Dan Scales <danscales@google.com>
Date: Wed, 8 Sep 2021 08:41:54 -0700
Subject: [release-branch.go1.17] cmd/compile: fix case where init info of OAS
 node is dropped

When an OAS node is converted to an OSELRECV2 node in tcSelect(), the
possible DCL node in the Init field was being dropped, since a
completely new node was being created and the Init field was not set. I
don't expect n.Init() to be set for the ORECV case, but the code now
deals with that too.

Fixed bug in both tcSelect() and transformSelect().

Cherry-picked from https://go-review.googlesource.com/c/go/+/348569

Fixes #49511

Change-Id: Id5b736daa8e90afda88aaa3769dde801db294c0d
Reviewed-on: https://go-review.googlesource.com/c/go/+/363664
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
---
 src/cmd/compile/internal/noder/transform.go |  9 +++++----
 src/cmd/compile/internal/typecheck/stmt.go  |  9 +++++----
 test/fixedbugs/issue48289.go                | 28 ++++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 8 deletions(-)
 create mode 100644 test/fixedbugs/issue48289.go

diff --git a/src/cmd/compile/internal/noder/transform.go b/src/cmd/compile/internal/noder/transform.go
index 2859089e69b..1a0c4d94c7e 100644
--- a/src/cmd/compile/internal/noder/transform.go
+++ b/src/cmd/compile/internal/noder/transform.go
@@ -495,10 +495,11 @@ func transformSelect(sel *ir.SelectStmt) {
 		if ncase.Comm != nil {
 			n := ncase.Comm
 			oselrecv2 := func(dst, recv ir.Node, def bool) {
-				n := ir.NewAssignListStmt(n.Pos(), ir.OSELRECV2, []ir.Node{dst, ir.BlankNode}, []ir.Node{recv})
-				n.Def = def
-				n.SetTypecheck(1)
-				ncase.Comm = n
+				selrecv := ir.NewAssignListStmt(n.Pos(), ir.OSELRECV2, []ir.Node{dst, ir.BlankNode}, []ir.Node{recv})
+				selrecv.Def = def
+				selrecv.SetTypecheck(1)
+				selrecv.SetInit(n.Init())
+				ncase.Comm = selrecv
 			}
 			switch n.Op() {
 			case ir.OAS:
diff --git a/src/cmd/compile/internal/typecheck/stmt.go b/src/cmd/compile/internal/typecheck/stmt.go
index 922a01bfbe9..2fc6d04e854 100644
--- a/src/cmd/compile/internal/typecheck/stmt.go
+++ b/src/cmd/compile/internal/typecheck/stmt.go
@@ -383,10 +383,11 @@ func tcSelect(sel *ir.SelectStmt) {
 			n := Stmt(ncase.Comm)
 			ncase.Comm = n
 			oselrecv2 := func(dst, recv ir.Node, def bool) {
-				n := ir.NewAssignListStmt(n.Pos(), ir.OSELRECV2, []ir.Node{dst, ir.BlankNode}, []ir.Node{recv})
-				n.Def = def
-				n.SetTypecheck(1)
-				ncase.Comm = n
+				selrecv := ir.NewAssignListStmt(n.Pos(), ir.OSELRECV2, []ir.Node{dst, ir.BlankNode}, []ir.Node{recv})
+				selrecv.Def = def
+				selrecv.SetTypecheck(1)
+				selrecv.SetInit(n.Init())
+				ncase.Comm = selrecv
 			}
 			switch n.Op() {
 			default:
diff --git a/test/fixedbugs/issue48289.go b/test/fixedbugs/issue48289.go
new file mode 100644
index 00000000000..94dbeee34cf
--- /dev/null
+++ b/test/fixedbugs/issue48289.go
@@ -0,0 +1,28 @@
+// run
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "fmt"
+
+func main() {
+	ch := make(chan int, 1)
+
+	var ptrs [2]*int
+	for i := range ptrs {
+		ch <- i
+		select {
+		case x := <-ch:
+			ptrs[i] = &x
+		}
+	}
+
+	for i, ptr := range ptrs {
+		if *ptr != i {
+			panic(fmt.Sprintf("got *ptr %d, want %d", *ptr, i))
+		}
+	}
+}
-- 
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