Filter out empty addresses in persistent_peers/seeds lists (#2323)

Fixes #2320

node/node_test.go

@@ -56,3 +56,22 @@ func TestNodeStartStop(t *testing.T) {
 		t.Fatal("timed out waiting for shutdown")
 	}
 }
+
+func TestSplitAndTrimEmpty(t *testing.T) {
+	testCases := []struct {
+		s        string
+		sep      string
+		cutset   string
+		expected []string
+	}{
+		{"a,b,c", ",", " ", []string{"a", "b", "c"}},
+		{" a , b , c ", ",", " ", []string{"a", "b", "c"}},
+		{" a, b, c ", ",", " ", []string{"a", "b", "c"}},
+		{" a, ", ",", " ", []string{"a"}},
+		{"   ", ",", " ", []string{}},
+	}
+
+	for _, tc := range testCases {
+		assert.Equal(t, tc.expected, splitAndTrimEmpty(tc.s, tc.sep, tc.cutset), "%s", tc.s)
+	}
+}