fixing mardown path navigation

Author: larsbrubaker

MarkdigAgg/AggMarkdownDocument.cs

@@ -418,6 +418,16 @@ public void UpdateCurrentDirectory(string newPath)
             }
         }
 
+        /// <summary>
+        /// Directly sets the working directory for relative link resolution without modifying basePath.
+        /// Used when navigating between articles within a known-safe document root.
+        /// </summary>
+        public void SetCurrentDirectory(string directory)
+        {
+            directory = directory.Replace('/', Path.DirectorySeparatorChar).TrimEnd(Path.DirectorySeparatorChar);
+            currentDirectory = Path.GetFullPath(directory);
+        }
+
         public string GetRelativePath(string fullPath)
         {
             return Path.GetRelativePath(currentDirectory, fullPath);

MarkdigAgg/MarkdownWidget.cs

@@ -210,12 +210,21 @@ public void SetContentUri(string contentUri)
 		{
 			if (!string.IsNullOrWhiteSpace(contentUri))
 			{
-				// Use the directory containing the file as the base path so relative links resolve correctly.
-				// If contentUri is already a directory, GetDirectoryName returns the parent, so check first.
 				var directory = File.Exists(contentUri)
 					? Path.GetDirectoryName(contentUri)
 					: contentUri;
-				pathHandler = new MarkdownPathHandler(directory);
+
+				if (pathHandler == null)
+				{
+					pathHandler = new MarkdownPathHandler(directory);
+				}
+				else
+				{
+					// Preserve the existing basePath (set at construction to the doc root) so that
+					// cross-directory relative links don't throw "outside base directory".
+					// Only shift currentDirectory to resolve links relative to the new article.
+					pathHandler.SetCurrentDirectory(directory);
+				}
 			}
 		}