From 59c36eb185f2eabebf4626f1f66fac1575493ca9 Mon Sep 17 00:00:00 2001
From: "miriam.baglioni" <miriam.baglioni@isti.cnr.it>
Date: Mon, 21 Jun 2021 10:41:47 +0200
Subject: [PATCH] check if pid is null (to avoid NullPointerException)

---
 .../src/main/java/eu/dnetlib/dhp/oa/merge/AuthorMerger.java     | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/AuthorMerger.java b/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/AuthorMerger.java
index 0b602b774..72b60e1d2 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/AuthorMerger.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/oa/merge/AuthorMerger.java
@@ -115,6 +115,8 @@ public class AuthorMerger {
 	}
 
 	public static String pidToComparableString(StructuredProperty pid) {
+		if (pid == null)
+			return "";
 		return (pid.getQualifier() != null
 			? pid.getQualifier().getClassid() != null ? pid.getQualifier().getClassid().toLowerCase() : ""
 			: "")