Index: src/wp-includes/js/wplink.js
===================================================================
--- src/wp-includes/js/wplink.js	(revision 32230)
+++ src/wp-includes/js/wplink.js	(working copy)
@@ -142,6 +142,8 @@
 		},
 
 		refresh: function() {
+			var text = '';
+
 			// Refresh rivers (clear links, check visibility)
 			rivers.search.refresh();
 			rivers.recent.refresh();
@@ -149,8 +151,21 @@
 			if ( wpLink.isMCE() ) {
 				wpLink.mceRefresh();
 			} else {
-				inputs.wrap.removeClass( 'has-text-field' );
-				inputs.text.val( '' );
+				// For the Text editor the "Link text" field is always shown
+				if ( ! inputs.wrap.hasClass( 'has-text-field' ) ) {
+					inputs.wrap.addClass( 'has-text-field' );
+				}
+
+				if ( document.selection ) {
+					// Old IE
+					text = document.selection.createRange().text || '';
+				} else if ( typeof this.textarea.selectionStart !== 'undefined' &&
+					( this.textarea.selectionStart !== this.textarea.selectionEnd ) ) {
+					// W3C
+					text = this.textarea.value.substring( this.textarea.selectionStart, this.textarea.selectionEnd ) || '';
+				}
+
+				inputs.text.val( text );
 				wpLink.setDefaultValues();
 			}