diff -ru nss.orig/nss/lib/certdb/crl.c nss/nss/lib/certdb/crl.c
--- nss/lib/certdb/crl.c	2016-02-12 15:36:18.000000000 +0100
+++ nss/lib/certdb/crl.c	2016-02-23 20:57:17.067924598 +0100
@@ -1982,7 +1982,7 @@
         return SECSuccess;
     }
     /* all CRLs are good, sort them by thisUpdate */
-    qsort(cache->crls, cache->ncrls, sizeof(CachedCrl*), SortCRLsByThisUpdate);
+    if (cache->ncrls != 0) qsort(cache->crls, cache->ncrls, sizeof(CachedCrl*), SortCRLsByThisUpdate);
 
     if (cache->ncrls) {
         /* pick the newest CRL */