--- a/src/hotspot/share/opto/ifnode.cpp	Tue Apr 30 12:54:07 2019 +0200
+++ b/src/hotspot/share/opto/ifnode.cpp	Tue Apr 30 14:49:19 2019 +0200
@@ -633,7 +633,7 @@
     if( din4->is_Call() &&      // Handle a slow-path call on either arm
         (din4 = din4->in(0)) )
       din4 = din4->in(0);
-    if( din3 == din4 && din3->is_If() )
+    if (din3 != NULL && din3 == din4 && din3->is_If()) // Regions not degraded to a copy
       return din3;              // Skip around diamonds
   }