From 7fea76c6c04f0ef44ac7a6dd0340a1ac5a18a3dd Mon Sep 17 00:00:00 2001
From: Francis Dupont <fdupont@isc.org>
Date: Wed, 22 Jul 2020 17:35:01 +0200
Subject: [PATCH] [#1333] Restored empty check

---
 src/lib/dhcpsrv/cfg_subnets4.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/lib/dhcpsrv/cfg_subnets4.cc b/src/lib/dhcpsrv/cfg_subnets4.cc
index 83870b0018..7c2ad2e98d 100644
--- a/src/lib/dhcpsrv/cfg_subnets4.cc
+++ b/src/lib/dhcpsrv/cfg_subnets4.cc
@@ -398,8 +398,10 @@ CfgSubnets4::selectSubnet(const std::string& iface,
         Subnet4Ptr subnet_selected;
 
         // First, try subnet specific interface name.
-       if ((*subnet)->getIface(Network4::Inheritance::NONE) == iface) {
-            subnet_selected = (*subnet);
+        if (!(*subnet)->getIface(Network4::Inheritance::NONE).empty()) {
+            if ((*subnet)->getIface(Network4::Inheritance::NONE) == iface) {
+                subnet_selected = (*subnet);
+            }
 
         } else {
             // Interface not specified for a subnet, so let's try if