azurerm_storage_account - fix crash in multichannel checking (hashi…

…corp#19298)

Relates-to: hashicorp#14736

internal/services/storage/storage_account_resource.go

@@ -647,6 +647,7 @@ func resourceStorageAccount() *pluginsdk.Resource {
 			"share_properties": {
 				Type:     pluginsdk.TypeList,
 				Optional: true,
+				// (@jackofallops) TODO - This should not be computed, however, this would be a breaking change with unknown implications for user data so needs to be addressed for 4.0
 				Computed: true,
 				MaxItems: 1,
 				Elem: &pluginsdk.Resource{
@@ -1344,17 +1345,22 @@ func resourceStorageAccountCreate(d *pluginsdk.ResourceData, meta interface{}) e
 		fileServiceClient := meta.(*clients.Client).Storage.FileServicesClient
 
 		shareProperties := expandShareProperties(val.([]interface{}))
+
 		// The API complains if any multichannel info is sent on non premium fileshares. Even if multichannel is set to false
-		if accountTier != string(storage.SkuTierPremium) {
+		if accountTier != string(storage.SkuTierPremium) && shareProperties.FileServicePropertiesProperties != nil && shareProperties.FileServicePropertiesProperties.ProtocolSettings != nil {
 
 			// Error if the user has tried to enable multichannel on a standard tier storage account
-			if shareProperties.FileServicePropertiesProperties.ProtocolSettings.Smb.Multichannel != nil && shareProperties.FileServicePropertiesProperties.ProtocolSettings.Smb.Multichannel.Enabled != nil {
-				if *shareProperties.FileServicePropertiesProperties.ProtocolSettings.Smb.Multichannel.Enabled {
-					return fmt.Errorf("`multichannel_enabled` isn't supported for Standard tier Storage accounts")
+			smb := shareProperties.FileServicePropertiesProperties.ProtocolSettings.Smb
+			if smb != nil && smb.Multichannel != nil {
+
+				if smb.Multichannel.Enabled != nil {
+					if *shareProperties.FileServicePropertiesProperties.ProtocolSettings.Smb.Multichannel.Enabled {
+						return fmt.Errorf("`multichannel_enabled` isn't supported for Standard tier Storage accounts")
+					}
 				}
-			}
 
-			shareProperties.FileServicePropertiesProperties.ProtocolSettings.Smb.Multichannel = nil
+				shareProperties.FileServicePropertiesProperties.ProtocolSettings.Smb.Multichannel = nil
+			}
 		}
 
 		if _, err = fileServiceClient.SetServiceProperties(ctx, id.ResourceGroup, id.Name, shareProperties); err != nil {

internal/services/storage/storage_account_resource_test.go

@@ -1350,6 +1350,21 @@ func TestAccStorageAccount_sasPolicy(t *testing.T) {
 	})
 }
 
+func TestAccStorageAccount_emptyShareProperties(t *testing.T) {
+	data := acceptance.BuildTestData(t, "azurerm_storage_account", "test")
+	r := StorageAccountResource{}
+
+	data.ResourceTest(t, r, []acceptance.TestStep{
+		{
+			Config: r.emptyShareProperties(data),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+			),
+		},
+		data.ImportStep(),
+	})
+}
+
 func TestAccStorageAccount_isSftpEnabled(t *testing.T) {
 	data := acceptance.BuildTestData(t, "azurerm_storage_account", "test")
 	r := StorageAccountResource{}
@@ -4131,6 +4146,31 @@ resource "azurerm_storage_account" "test" {
 `, data.RandomInteger, data.Locations.Primary, data.RandomString)
 }
 
+func (r StorageAccountResource) emptyShareProperties(data acceptance.TestData) string {
+	return fmt.Sprintf(`
+provider "azurerm" {
+  features {}
+}
+
+resource "azurerm_resource_group" "test" {
+  name     = "acctestRG-storage-%[1]d"
+  location = "%[2]s"
+}
+
+resource "azurerm_storage_account" "test" {
+  name                = "unlikely23exst2acct%[3]s"
+  resource_group_name = azurerm_resource_group.test.name
+
+  location                 = azurerm_resource_group.test.location
+  account_tier             = "Standard"
+  account_replication_type = "LRS"
+  account_kind             = "StorageV2"
+
+  share_properties {}
+}
+`, data.RandomInteger, data.Locations.Primary, data.RandomString)
+}
+
 func (r StorageAccountResource) isSftpEnabledTrue(data acceptance.TestData) string {
 	return fmt.Sprintf(`
 provider "azurerm" {