From e1ac83f7d89b2cc3fc0bf1c028b6373780e029ae Mon Sep 17 00:00:00 2001
From: Marc Vertes <mvertes@free.fr>
Date: Tue, 17 Dec 2019 10:18:06 +0100
Subject: [PATCH] fix: correct type extraction for returned value

---
 _test/nil0.go | 15 +++++++++++++++
 interp/cfg.go | 25 ++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 _test/nil0.go

diff --git a/_test/nil0.go b/_test/nil0.go
new file mode 100644
index 000000000..f631a14f9
--- /dev/null
+++ b/_test/nil0.go
@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func f() (host, port string, err error) {
+	return "", "", nil
+}
+
+func main() {
+	h, p, err := f()
+	fmt.Println(h, p, err)
+}
+
+// Output:
+//   <nil>
diff --git a/interp/cfg.go b/interp/cfg.go
index 801ff5b11..0446e6ad3 100644
--- a/interp/cfg.go
+++ b/interp/cfg.go
@@ -1068,7 +1068,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 					// nil: Set node value to zero of return type
 					f := sc.def
 					var typ *itype
-					if typ, err = nodeType(interp, sc, f.child[2].child[1].child[i].lastChild()); err != nil {
+					if typ, err = nodeType(interp, sc, f.child[2].child[1].fieldType(i)); err != nil {
 						return
 					}
 					if typ.cat == funcT {
@@ -1643,6 +1643,29 @@ func (n *node) isNatural() bool {
 	return false
 }
 
+// fieldType returns the nth parameter field node (type) of a fieldList node
+func (n *node) fieldType(m int) *node {
+	k := 0
+	l := len(n.child)
+	for i := 0; i < l; i++ {
+		cl := len(n.child[i].child)
+		if cl < 2 {
+			if k == m {
+				return n.child[i].lastChild()
+			}
+			k++
+			continue
+		}
+		for j := 0; j < cl-1; j++ {
+			if k == m {
+				return n.child[i].lastChild()
+			}
+			k++
+		}
+	}
+	return nil
+}
+
 // lastChild returns the last child of a node
 func (n *node) lastChild() *node { return n.child[len(n.child)-1] }