Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 3897)
+++ /CKEditor/trunk/CHANGES.html	(revision 3898)
@@ -131,4 +131,5 @@
 		<li><a href="http://dev.fckeditor.net/ticket/3671">#3671</a> : Fixed body fixing should be applied to the real type under fake elements.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/3836">#3836</a> : Fixed remove list in enterMode=BR will merge sibling text to one line.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/3949">#3949</a> : Fixed enterKey within pre-formatted text introduce wrong line-break.</li>
 	</ul>
 	<h3>
Index: /CKEditor/trunk/_source/plugins/selection/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/selection/plugin.js	(revision 3897)
+++ /CKEditor/trunk/_source/plugins/selection/plugin.js	(revision 3898)
@@ -492,5 +492,8 @@
 
 						testRange.setEndPoint( 'StartToStart', range );
-						var distance = testRange.text.length;
+						// IE report line break as CRLF with range.text but
+						// only LF with textnode.nodeValue, normalize them to avoid
+						// breaking character counting logic below. (#3949)
+						var distance = testRange.text.replace( /(\r\n|\r)/g, '\n' ).length;
 
 						while ( distance > 0 )
@@ -944,5 +947,5 @@
 	CKEDITOR.env.ie ?
 		// V2
-		function()
+		function( forceExpand )
 		{
 			var collapsed = this.collapsed;
@@ -984,5 +987,5 @@
 				// Actually, we are using this flag just to avoid using this hack in all
 				// situations, but just on those needed.
-				isStartMarkerAlone = !startNode.hasPrevious() || ( startNode.getPrevious().is && startNode.getPrevious().is( 'br' ) );
+				isStartMarkerAlone = forceExpand || !startNode.hasPrevious() || ( startNode.getPrevious().is && startNode.getPrevious().is( 'br' ) );
 
 				// Append a temporary <span>&#65279;</span> before the selection.