Fixed local source links being refused by Word and LibreOffice

app/MindWork AI Studio/Tools/FileExportFormatExtensions.cs

@@ -204,6 +204,26 @@ public static class FileExportFormatExtensions
         _ => WITHOUT_BYTE_ORDER_MARK,
     };
 
+    /// <summary>
+    /// Determines whether a link into a local file may name the page it points at.
+    /// </summary>
+    /// <remarks>
+    /// A page is named by the fragment of the link, the way the PDF open parameters call for. A
+    /// browser and a PDF reader follow that and open the document on the page; Word and LibreOffice
+    /// take the fragment for part of the file name, look for a file which does not exist, and refuse
+    /// the link altogether. There the page is dropped, so the link at least opens the document --
+    /// which page it was stays in the title of the source. Verified on 2026-09-15 with LibreOffice
+    /// on an exported .odt. A format added later keeps the page unless it is known to stumble too.
+    /// </remarks>
+    /// <param name="format">The format.</param>
+    /// <returns>True, when a reader of this format follows such a link.</returns>
+    public static bool FollowsPageAnchors(this FileExportFormat format) => format switch
+    {
+        FileExportFormat.MICROSOFT_WORD or FileExportFormat.OPEN_DOCUMENT_TEXT => false,
+
+        _ => true,
+    };
+
     /// <summary>
     /// Returns the name Pandoc knows the format by.
     /// </summary>

app/MindWork AI Studio/Tools/PandocExport.cs

@@ -118,7 +118,7 @@ public static class PandocExport
         // We read the text before we ask for a path: when there is nothing to convert, the user
         // should learn that right away instead of picking a file first and getting an error afterwards.
         //
-        if (!markdownContent.TryGetExportMarkdown(out var markdownText))
+        if (!markdownContent.TryGetExportMarkdown(out var markdownText, format.FollowsPageAnchors()))
         {
             LOGGER.LogWarning("Cannot export the content as {ExportFormat}, because it carries no text.", format);
             await MessageBus.INSTANCE.SendError(new(Icons.Material.Filled.Cancel, TB("Only text messages can be exported.")));

app/MindWork AI Studio/Tools/SourceExtensions.cs

@@ -138,8 +138,9 @@ public static partial class SourceExtensions
     /// Converts a list of sources to a markdown-formatted string.
     /// </summary>
     /// <param name="sources">The list of sources to convert.</param>
+    /// <param name="keepPageAnchors">Whether a link into a local file may name its page; see the method below.</param>
     /// <returns>A markdown-formatted string representing the sources.</returns>
-    public static string ToMarkdown(this IList<Source> sources)
+    public static string ToMarkdown(this IList<Source> sources, bool keepPageAnchors = true)
     {
         var sb = new StringBuilder();
         foreach (var group in sources.GroupSources())
@@ -152,8 +153,9 @@ public static partial class SourceExtensions
 
             foreach (var numberedSource in group.Sources)
             {
+                var url = keepPageAnchors ? numberedSource.Source.URL : WithoutPageAnchor(numberedSource.Source.URL);
                 sb.Append($"- [{numberedSource.Number}] ");
-                AppendMarkdownLink(sb, numberedSource.Source.Title, numberedSource.Source.URL);
+                AppendMarkdownLink(sb, numberedSource.Source.Title, url);
                 sb.AppendLine();
             }
         }
@@ -161,6 +163,29 @@ public static partial class SourceExtensions
         return sb.ToString();
     }
 
+    /// <summary>
+    /// Takes the page off a link into a local file, for a reader which cannot follow it.
+    /// </summary>
+    /// <remarks>
+    /// Everything a local link carries in its fragment is dropped, not only a page: a chunk is no
+    /// use to any reader either, and what breaks such a link is the fragment itself rather than what
+    /// stands in it. A web address keeps its fragment untouched, because there the fragment is part
+    /// of the address and naming a section of a page is exactly what it is for.
+    /// </remarks>
+    /// <param name="url">The link of the source.</param>
+    /// <returns>The link without its fragment, or the link itself when it carries none.</returns>
+    private static string WithoutPageAnchor(string url)
+    {
+        if (string.IsNullOrWhiteSpace(url))
+            return url;
+
+        var cleanedUrl = url.Trim().Replace("\r", string.Empty).Replace("\n", string.Empty);
+        if (!Uri.TryCreate(cleanedUrl, UriKind.Absolute, out var absoluteUri) || !absoluteUri.IsFile || absoluteUri.Fragment.Length == 0)
+            return url;
+
+        return absoluteUri.GetComponents(UriComponents.AbsoluteUri & ~UriComponents.Fragment, UriFormat.UriEscaped);
+    }
+
     /// <summary>
     /// Converts a list of sources to a markdown-formatted string, headed by a title of its own.
     /// </summary>
@@ -171,10 +196,11 @@ public static partial class SourceExtensions
     /// for this and the chat does not.
     /// </remarks>
     /// <param name="sources">The list of sources to convert.</param>
+    /// <param name="keepPageAnchors">Whether a link into a local file may name its page.</param>
     /// <returns>A markdown-formatted string representing the sources, or an empty string when there are none.</returns>
-    public static string ToExportMarkdown(this IList<Source> sources)
+    public static string ToExportMarkdown(this IList<Source> sources, bool keepPageAnchors = true)
     {
-        var sourcesMarkdown = sources.ToMarkdown();
+        var sourcesMarkdown = sources.ToMarkdown(keepPageAnchors);
         if (string.IsNullOrWhiteSpace(sourcesMarkdown))
             return string.Empty;