--- RollingFileAppender.cs.old	2005-02-07 22:33:34.000000000 +1100
+++ RollingFileAppender.cs	2006-01-17 16:23:13.788267200 +1100
@@ -453,6 +453,26 @@
 			set { m_staticLogFileName = value; }
 		}
 
+		/// <summary>
+		/// Gets or sets a value indicating whether to preserve the file name extension when rolling.
+		/// </summary>
+		/// <value>
+		/// <c>true</c> if the file name extension should be preserved.
+		/// </value>
+		/// <remarks>
+		/// <para>
+		/// By default file.log is rolled to file.log.yyyy-mm-dd or file.log.curSizeRollBackup.
+		/// However, under Windows the new file name will loose any program associations as the
+		/// extension is changed. Optionally file.log can be renamed to file.yyyy-mm-dd.log or
+		/// file.curSizeRollBackup.log to maintain any program associations.
+		/// </para>
+		/// </remarks>
+		public bool PreserveLogFileNameExtension
+		{
+			get { return m_preserveLogFileNameExtension; }
+			set { m_preserveLogFileNameExtension = value; }
+		}
+
 		#endregion Public Instance Properties
 
 		#region Override implementation of FileAppender 
@@ -973,6 +993,19 @@
   
 		#region Roll File
 
+		private string CombinePath(string path1, string path2)
+		{
+			string extension = Path.GetExtension(path1);
+			if (m_preserveLogFileNameExtension && extension.Length > 0)
+			{
+				return Path.GetFileNameWithoutExtension(path1) + path2 + extension;
+			}
+			else
+			{
+				return path1 + path2;
+			}
+		}
+
 		/// <summary>
 		/// Rollover the file(s) to date/time tagged file(s).
 		/// </summary>
@@ -999,12 +1032,12 @@
 				//something has gone wrong if we hit this -- we should only
 				//roll over if the new file will be different from the old
 				string dateFormat = m_now.ToString(m_datePattern, System.Globalization.DateTimeFormatInfo.InvariantInfo);
-				if (m_scheduledFilename.Equals(File + dateFormat)) 
+				if (m_scheduledFilename.Equals(CombinePath(File, dateFormat))) 
 				{
-					ErrorHandler.Error("Compare " + m_scheduledFilename + " : " + File + dateFormat);
+					ErrorHandler.Error("Compare " + m_scheduledFilename + " : " + CombinePath(File, dateFormat));
 					return;
 				}
-	  
+ 
 				if (fileIsOpen)
 				{
 					// close current file, and rename it to datedFilename
@@ -1014,8 +1047,8 @@
 				//we may have to roll over a large number of backups here
 				for (int i = 1; i <= m_curSizeRollBackups; i++) 
 				{
-					string from = File + '.' + i;
-					string to = m_scheduledFilename + '.' + i;
+					string from = CombinePath(File, "." + i);
+					string to = CombinePath(m_scheduledFilename, "." + i);
 					RollFile(from, to);
 				}
 	  
@@ -1026,7 +1059,7 @@
 			m_curSizeRollBackups = 0; 
 	
 			//new scheduled name
-			m_scheduledFilename = File + m_now.ToString(m_datePattern, System.Globalization.DateTimeFormatInfo.InvariantInfo);
+			m_scheduledFilename = CombinePath(File, m_now.ToString(m_datePattern, System.Globalization.DateTimeFormatInfo.InvariantInfo));
 
 			if (fileIsOpen)
 			{
@@ -1230,20 +1263,20 @@
 					// Delete the oldest file, to keep Windows happy.
 					if (m_curSizeRollBackups == m_maxSizeRollBackups) 
 					{
-						DeleteFile(baseFileName + '.' + m_maxSizeRollBackups);
+						DeleteFile(CombinePath(baseFileName , "." + m_maxSizeRollBackups));
 						m_curSizeRollBackups--;
 					}
 	
 					// Map {(maxBackupIndex - 1), ..., 2, 1} to {maxBackupIndex, ..., 3, 2}
 					for (int i = m_curSizeRollBackups; i >= 1; i--) 
 					{
-						RollFile((baseFileName + "." + i), (baseFileName + '.' + (i + 1)));
+						RollFile((CombinePath(baseFileName, "." + i)), (CombinePath(baseFileName, "." + (i + 1))));
 					}
 	
 					m_curSizeRollBackups++;
 
 					// Rename fileName to fileName.1
-					RollFile(baseFileName, baseFileName + ".1");
+					RollFile(baseFileName, CombinePath(baseFileName, ".1"));
 				} 
 				else 
 				{
@@ -1252,13 +1285,13 @@
 					{
 						//delete the first and keep counting up.
 						int oldestFileIndex = m_curSizeRollBackups - m_maxSizeRollBackups + 1;
-						DeleteFile(baseFileName + '.' + oldestFileIndex);
+						DeleteFile(CombinePath(baseFileName, "." + oldestFileIndex));
 					}
 	
 					if (m_staticLogFileName) 
 					{
 						m_curSizeRollBackups++;
-						RollFile(baseFileName, baseFileName + '.' + m_curSizeRollBackups);
+						RollFile(baseFileName, CombinePath(baseFileName, "." + m_curSizeRollBackups));
 					}
 				}
 			}
@@ -1423,6 +1456,11 @@
 		private bool m_staticLogFileName = true;
   
 		/// <summary>
+		/// Value indicating whether to preserve the file name extension when rolling.
+		/// </summary>
+		private bool m_preserveLogFileNameExtension = false;
+
+		/// <summary>
 		/// FileName provided in configuration.  Used for rolling properly
 		/// </summary>
 		private string m_baseFileName;