From 32a332fd3f79299af9f89f836a8d64e1ed4eb831 Mon Sep 17 00:00:00 2001
From: Fabian Jakobs <fabian.jakobs@web.de>
Date: Sat, 12 Feb 2011 13:13:35 +0100
Subject: [PATCH] fix desired column computation

---
 lib/ace/anchor.js    | 10 +++++++++-
 lib/ace/selection.js |  8 ++++----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/lib/ace/anchor.js b/lib/ace/anchor.js
index 1be42e22..f0a02183 100644
--- a/lib/ace/anchor.js
+++ b/lib/ace/anchor.js
@@ -138,9 +138,17 @@ var Anchor = exports.Anchor = function(doc, row, column) {
         if (this.row == pos.row && this.column == pos.column)
             return;
             
+        var old = {
+            row: this.row,
+            column: this.column
+        };
+        
         this.row = pos.row;
         this.column = pos.column;
-        this._dispatchEvent("change");
+        this._dispatchEvent("change", {
+            old: old,
+            value: pos
+        });
     };
     
     this.detach = function() {
diff --git a/lib/ace/selection.js b/lib/ace/selection.js
index 12453a3e..a130228d 100644
--- a/lib/ace/selection.js
+++ b/lib/ace/selection.js
@@ -53,10 +53,12 @@ var Selection = function(session) {
     this.selectionAnchor = new Anchor(this.doc, 0, 0);
     
     var _self = this;
-    this.selectionLead.on("change", function() {
+    this.selectionLead.on("change", function(e) {
         _self._dispatchEvent("changeCursor");
         if (!_self.$isEmpty)
             _self._dispatchEvent("changeSelection");
+        if (e.old.row == e.value.row)
+            _self.$updateDesiredColumn();
     });
     
     this.selectionAnchor.on("change", function() {
@@ -176,9 +178,7 @@ var Selection = function(session) {
 
     this.$updateDesiredColumn = function() {
         var cursor = this.getCursor();
-        if (cursor) {
-            this.$desiredColumn = this.session.documentToScreenColumn(cursor.row, cursor.column);
-        }
+        this.$desiredColumn = this.session.documentToScreenColumn(cursor.row, cursor.column);
     };
 
     this.$moveSelection = function(mover) {