From f2034819c27c3dda6290dfbd3a4158a6874835db Mon Sep 17 00:00:00 2001
From: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Date: Thu, 25 Jul 2019 01:20:04 +0700
Subject: [PATCH] fix: blank identifier cause panic (#255)

---
 _test/assign8.go | 9 +++++++++
 interp/cfg.go    | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 _test/assign8.go

diff --git a/_test/assign8.go b/_test/assign8.go
new file mode 100644
index 00000000..75f258dc
--- /dev/null
+++ b/_test/assign8.go
@@ -0,0 +1,9 @@
+package main
+
+func main() {
+	_ = 1
+	println(1)
+}
+
+// Output:
+// 1
diff --git a/interp/cfg.go b/interp/cfg.go
index 5b1b4bd4..82038622 100644
--- a/interp/cfg.go
+++ b/interp/cfg.go
@@ -343,7 +343,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				dest, src := n.child[i], n.child[sbase+i]
 				var sym *symbol
 				var level int
-				if n.kind == defineStmt {
+				if n.kind == defineStmt || (n.kind == assignStmt && dest.ident == "_") {
 					if src.typ != nil && src.typ.cat == nilT {
 						err = src.cfgErrorf("use of untyped nil")
 						break