From 7177c252616dd1e48aafb85ebfb5dff229d72444 Mon Sep 17 00:00:00 2001
From: "miriam.baglioni" <miriam.baglioni@isti.cnr.it>
Date: Mon, 5 Jul 2021 16:22:38 +0200
Subject: [PATCH] added check for null value during doi normalization

---
 .../src/main/java/eu/dnetlib/doiboost/DoiBoostMappingUtil.scala | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/DoiBoostMappingUtil.scala b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/DoiBoostMappingUtil.scala
index 1baf55b89..12e4ac379 100644
--- a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/DoiBoostMappingUtil.scala
+++ b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/DoiBoostMappingUtil.scala
@@ -358,6 +358,8 @@ object DoiBoostMappingUtil {
   def isEmpty(x: String) = x == null || x.trim.isEmpty
 
   def normalizeDoi(input : String) :String ={
+    if(input == null)
+      return null
     val replaced = input.replaceAll("(?:\\n|\\r|\\t|\\s)", "").toLowerCase.replaceFirst(DOI_PREFIX_REGEX, DOI_PREFIX)
     if  (isEmpty(replaced))
       return null