Preview: Fixes a potential issue where the preview URL could be a different backoffice host

src/Umbraco.Cms.Api.Management/Factories/DocumentUrlFactory.cs

@@ -39,7 +39,7 @@ public async Task<IEnumerable<DocumentUrlInfo>> CreateUrlsAsync(IContent content
     {
         ISet<UrlInfo> urlInfos = await _publishedUrlInfoProvider.GetAllAsync(content);
         return urlInfos
-            .Select(urlInfo => CreateDocumentUrlInfo(urlInfo, false))
+            .Select(CreateDocumentUrlInfo)
             .ToArray();
     }
 
@@ -89,18 +89,16 @@ public async Task<IEnumerable<DocumentUrlInfoResponseModel>> CreateUrlSetsAsync(
             }
         }
 
-        return CreateDocumentUrlInfo(previewUrlInfo, previewUrlInfo.IsExternal is false);
+        return CreateDocumentUrlInfo(previewUrlInfo);
     }
 
-    private DocumentUrlInfo CreateDocumentUrlInfo(UrlInfo urlInfo, bool ensureAbsoluteUrl)
+    private DocumentUrlInfo CreateDocumentUrlInfo(UrlInfo urlInfo)
     {
         var url = urlInfo.Url?.ToString();
         return new DocumentUrlInfo
         {
             Culture = urlInfo.Culture,
-            Url = ensureAbsoluteUrl && url is not null
-                ? _absoluteUrlBuilder.ToAbsoluteUrl(url).ToString()
-                : url,
+            Url = url,
             Message = urlInfo.Message,
             Provider = urlInfo.Provider,
         };

src/Umbraco.Core/Routing/NewDefaultUrlProvider.cs

@@ -144,7 +144,7 @@ public virtual IEnumerable<UrlInfo> GetOtherUrls(int id, Uri current)
     public Task<UrlInfo?> GetPreviewUrlAsync(IContent content, string? culture, string? segment)
         => Task.FromResult<UrlInfo?>(
             UrlInfo.AsUrl(
-                $"/{Constants.System.UmbracoPathSegment}/preview?id={content.Key}&culture={culture}&segment={segment}",
+                $"/preview?id={content.Key}&culture={culture}&segment={segment}",
                 Alias,
                 culture,
                 isExternal: false));
@@ -182,7 +182,7 @@ private string GetLegacyRouteFormatById(Guid key, string? culture)
         // We have the published content now, so we can check if the culture is published, and thus avoid the DB hit.
         string route;
         var isDraft = _umbracoContextAccessor.GetRequiredUmbracoContext().InPreviewMode;
-        if(isDraft is false && string.IsNullOrWhiteSpace(culture) is false && content.Cultures.Any() && content.IsInvariantOrHasCulture(culture) is false)
+        if (isDraft is false && string.IsNullOrWhiteSpace(culture) is false && content.Cultures.Any() && content.IsInvariantOrHasCulture(culture) is false)
         {
             route = "#";
         }

src/Umbraco.Web.UI.Client/src/packages/documents/documents/workspace/document-workspace.context.ts

@@ -40,6 +40,7 @@
 import type { UmbEntityModel } from '@umbraco-cms/backoffice/entity';
 import type { UmbVariantPropertyGuardRule } from '@umbraco-cms/backoffice/property';
 import { UMB_ACTION_EVENT_CONTEXT } from '@umbraco-cms/backoffice/action';
+import { UMB_SERVER_CONTEXT } from '@umbraco-cms/backoffice/server';
 
 type ContentModel = UmbDocumentDetailModel;
 type ContentTypeModel = UmbDocumentTypeDetailModel;
@@ -344,7 +345,16 @@
 		);
 
 		if (previewUrlData.url) {
-			const previewWindow = window.open(previewUrlData.url, `umbpreview-${unique}`);
+			let previewUrl = previewUrlData.url;
+
+			const serverContext = await this.getContext(UMB_SERVER_CONTEXT);
+			const backofficePath = serverContext?.getBackofficePath() ?? '/';
+
+			if (!previewUrlData.url.startsWith(backofficePath)) {
+				previewUrl = `${backofficePath}${previewUrlData.url}`;
+			}
+
+			const previewWindow = window.open(previewUrl, `umbpreview-${unique}`);
 			previewWindow?.focus();
 			return;
 		}