Fix for Bugs #8227, #11226 - subnet info lost on vNet update

builtin/providers/azurerm/resource_arm_virtual_network.go

@@ -293,7 +293,6 @@ func resourceAzureSubnetHash(v interface{}) int {
 	}
 	return hashcode.String(subnet)
 }
-
 func getExistingSubnet(resGroup string, vnetName string, subnetName string, meta interface{}) network.Subnet {
 	//attempt to retrieve existing subnet from the server
 	existingSubnet := network.Subnet{}
@@ -328,3 +327,41 @@ func getExistingSubnet(resGroup string, vnetName string, subnetName string, meta
 
 	return existingSubnet
 }
+
+func expandAzureRmVirtualNetworkVirtualNetworkSecurityGroupNames(d *schema.ResourceData) ([]string, error) {
+	nsgNames := make([]string, 0)
+
+	if v, ok := d.GetOk("subnet"); ok {
+		subnets := v.(*schema.Set).List()
+		for _, subnet := range subnets {
+			subnet, ok := subnet.(map[string]interface{})
+			if !ok {
+				return nil, fmt.Errorf("[ERROR] Subnet should be a Hash - was '%+v'", subnet)
+			}
+
+			networkSecurityGroupId := subnet["security_group"].(string)
+			if networkSecurityGroupId != "" {
+				nsgName, err := parseNetworkSecurityGroupName(networkSecurityGroupId)
+				if err != nil {
+					return nil, err
+				}
+
+				nsgNames = append(nsgNames, nsgName)
+			}
+		}
+	}
+
+	return nsgNames, nil
+}
+
+func azureRMVirtualNetworkUnlockNetworkSecurityGroups(networkSecurityGroupNames *[]string) {
+	for _, networkSecurityGroupName := range *networkSecurityGroupNames {
+		armMutexKV.Unlock(networkSecurityGroupName)
+	}
+}
+
+func azureRMVirtualNetworkLockNetworkSecurityGroups(networkSecurityGroupNames *[]string) {
+	for _, networkSecurityGroupName := range *networkSecurityGroupNames {
+		armMutexKV.Lock(networkSecurityGroupName)
+	}
+}