config: removeCurrent finds the proper map

config/interpolate_walk.go

@@ -195,19 +195,24 @@ func (w *interpolationWalker) Primitive(v reflect.Value) error {
 }
 
 func (w *interpolationWalker) removeCurrent() {
-	c := w.cs[len(w.cs)-1]
-	switch c.Kind() {
-	case reflect.Map:
-		// Zero value so that we delete the map key
-		var val reflect.Value
-
-		// Get the key and delete it
-		k := w.csData.(reflect.Value)
-		c.SetMapIndex(k, val)
-	}
-
 	// Append the key to the unknown keys
 	w.unknownKeys = append(w.unknownKeys, strings.Join(w.key, "."))
+
+	for i := 1; i <= len(w.cs); i++ {
+		c := w.cs[len(w.cs)-i]
+		switch c.Kind() {
+		case reflect.Map:
+			// Zero value so that we delete the map key
+			var val reflect.Value
+
+			// Get the key and delete it
+			k := w.csData.(reflect.Value)
+			c.SetMapIndex(k, val)
+			return
+		}
+	}
+
+	panic("No container found for removeCurrent")
 }
 
 func (w *interpolationWalker) replaceCurrent(v reflect.Value) {

config/interpolate_walk_test.go

@@ -188,6 +188,17 @@ func TestInterpolationWalker_replace(t *testing.T) {
 			},
 			Value: "bar" + InterpSplitDelim + "baz",
 		},
+
+		{
+			Input: map[string]interface{}{
+				"foo": []interface{}{
+					"${var.foo}",
+					"bing",
+				},
+			},
+			Output: map[string]interface{}{},
+			Value: UnknownVariableValue + InterpSplitDelim + "baz",
+		},
 	}
 
 	for i, tc := range cases {