[Bug:] azurerm_cdn_frontdoor_route - cdn_frontdoor_origin_path gets removed on update if unchanged.

internal/services/cdn/cdn_frontdoor_route_resource.go

@@ -455,11 +455,12 @@ func resourceCdnFrontDoorRouteUpdate(d *pluginsdk.ResourceData, meta interface{}
 		}
 	}
 
-	// NOTE: You need to always pass these two on update else you will
-	// disable your cache and disassociate your custom domains...
+	// NOTE: You need to always pass these three on update else you will
+	// disable your cache, disassociate your custom domains or remove your origin path...
 	updateProps := azuresdkhacks.RouteUpdatePropertiesParameters{
 		CustomDomains:      existing.RouteProperties.CustomDomains,
 		CacheConfiguration: existing.RouteProperties.CacheConfiguration,
+		OriginPath:         existing.RouteProperties.OriginPath,
 	}
 
 	if d.HasChange("cache") {
@@ -491,6 +492,8 @@ func resourceCdnFrontDoorRouteUpdate(d *pluginsdk.ResourceData, meta interface{}
 	}
 
 	if d.HasChange("cdn_frontdoor_origin_path") {
+		updateProps.OriginPath = nil
+
 		originPath := d.Get("cdn_frontdoor_origin_path").(string)
 		if originPath != "" {
 			updateProps.OriginPath = utils.String(originPath)

internal/services/cdn/cdn_frontdoor_route_resource_test.go

@@ -85,6 +85,30 @@ func TestAccCdnFrontDoorRoute_update(t *testing.T) {
 	})
 }
 
+func TestAccCdnFrontDoorRoute_originPath(t *testing.T) {
+	// regression test case for issue #24466
+	data := acceptance.BuildTestData(t, "azurerm_cdn_frontdoor_route", "test")
+	r := CdnFrontDoorRouteResource{}
+	data.ResourceTest(t, r, []acceptance.TestStep{
+		{
+			Config: r.completeNoCache(data),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+				check.That(data.ResourceName).Key("cdn_frontdoor_origin_path").HasValue("/example"),
+			),
+		},
+		data.ImportStep("cdn_frontdoor_origin_group_id", "cdn_frontdoor_origin_ids"),
+		{
+			Config: r.complete(data),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+				check.That(data.ResourceName).Key("cdn_frontdoor_origin_path").HasValue("/example"),
+			),
+		},
+		data.ImportStep("cdn_frontdoor_origin_group_id", "cdn_frontdoor_origin_ids"),
+	})
+}
+
 func (r CdnFrontDoorRouteResource) Exists(ctx context.Context, clients *clients.Client, state *pluginsdk.InstanceState) (*bool, error) {
 	id, err := parse.FrontDoorRouteID(state.ID)
 	if err != nil {
@@ -216,6 +240,28 @@ resource "azurerm_cdn_frontdoor_route" "test" {
 `, template, data.RandomInteger)
 }
 
+func (r CdnFrontDoorRouteResource) completeNoCache(data acceptance.TestData) string {
+	template := r.template(data)
+	return fmt.Sprintf(`
+%s
+
+resource "azurerm_cdn_frontdoor_route" "test" {
+  name                          = "accTestRoute-%d"
+  cdn_frontdoor_endpoint_id     = azurerm_cdn_frontdoor_endpoint.test.id
+  cdn_frontdoor_origin_group_id = azurerm_cdn_frontdoor_origin_group.test.id
+  cdn_frontdoor_origin_ids      = [azurerm_cdn_frontdoor_origin.test.id]
+  cdn_frontdoor_rule_set_ids    = [azurerm_cdn_frontdoor_rule_set.test.id]
+  cdn_frontdoor_origin_path     = "/example"
+
+  enabled                = true
+  forwarding_protocol    = "HttpsOnly"
+  https_redirect_enabled = true
+  patterns_to_match      = ["/*"]
+  supported_protocols    = ["Http", "Https"]
+}
+`, template, data.RandomInteger)
+}
+
 func (r CdnFrontDoorRouteResource) update(data acceptance.TestData) string {
 	template := r.template(data)
 	return fmt.Sprintf(`