fix(azure): guard remaining nil derefs in loadbalancer, region, virtualnetwork

Extend the PR's nil-safety pass to three sites missed in the initial sweep:
- GetIPOfLoadBalancerFrontendIPConfigWithClient: nil-check feConfig arg
- GetAllAzureRegionsContextE: skip nil region in pager loop
- GetVirtualNetworkSubnetsWithClient: skip nil element in subnet pager loop

Author: james00012

modules/azure/loadbalancer.go

@@ -298,7 +298,7 @@ func ExtractLoadBalancerFrontendIPConfigNames(lb *armnetwork.LoadBalancer) []str
 // specified Frontend IP Configuration. For public IPs it requires a PublicIPAddressesClient
 // to resolve the public IP address.
 func GetIPOfLoadBalancerFrontendIPConfigWithClient(ctx context.Context, feConfig *armnetwork.FrontendIPConfiguration, pipClient *armnetwork.PublicIPAddressesClient, resourceGroupName string) (string, LoadBalancerIPType, error) {
-	if feConfig.Properties == nil {
+	if feConfig == nil || feConfig.Properties == nil {
 		return "", NoIP, errors.New("frontend IP configuration has nil properties")
 	}
 

modules/azure/region.go

@@ -208,9 +208,11 @@ func GetAllAzureRegionsContextE(t testing.TestingT, ctx context.Context, subscri
 		}
 
 		for _, region := range page.Value {
-			if region.Name != nil {
-				regions = append(regions, *region.Name)
+			if region == nil || region.Name == nil {
+				continue
 			}
+
+			regions = append(regions, *region.Name)
 		}
 	}
 

modules/azure/virtualnetwork.go

@@ -212,7 +212,7 @@ func GetVirtualNetworkSubnetsWithClient(ctx context.Context, client *armnetwork.
 		}
 
 		for _, v := range page.Value {
-			if v.Name == nil || v.Properties == nil || v.Properties.AddressPrefix == nil {
+			if v == nil || v.Name == nil || v.Properties == nil || v.Properties.AddressPrefix == nil {
 				continue
 			}