diff --git a/src/ace/Selection.js b/src/ace/Selection.js
index f4ba4be7..f29cf1b8 100644
--- a/src/ace/Selection.js
+++ b/src/ace/Selection.js
@@ -67,18 +67,29 @@ ace.Selection = function(doc) {
         var anchor = this.getSelectionAnchor();
         var lead = this.getSelectionLead();
 
-        this.setSelectionAnchor(anchor.row, anchor.column + columns);
-        this.$moveSelection(function() {
-            this.moveCursorTo(lead.row, lead.column + columns);
-        });
+        var isBackwards = this.$isBackwards();
+
+        if (!isBackwards || anchor.column !== 0)
+            this.setSelectionAnchor(anchor.row, anchor.column + columns);
+
+        if (isBackwards || lead.column !== 0) {
+            this.$moveSelection(function() {
+                this.moveCursorTo(lead.row, lead.column + columns);
+            });
+        }
+    };
+
+    this.$isBackwards = function() {
+        var anchor = this.selectionAnchor || this.selectionLead;
+        var lead = this.selectionLead;
+        return (anchor.row > lead.row || (anchor.row == lead.row && anchor.column > lead.column));
     };
 
     this.getRange = function() {
         var anchor = this.selectionAnchor || this.selectionLead;
         var lead = this.selectionLead;
 
-        if (anchor.row > lead.row
-                || (anchor.row == lead.row && anchor.column > lead.column)) {
+        if (this.$isBackwards()) {
             return ace.Range.fromPoints(lead, anchor);
         }
         else {
diff --git a/src/ace/mode/JavaScript.js b/src/ace/mode/JavaScript.js
index 35329f03..e8076ab6 100644
--- a/src/ace/mode/JavaScript.js
+++ b/src/ace/mode/JavaScript.js
@@ -9,11 +9,32 @@ ace.inherits(ace.mode.JavaScript, ace.mode.Text);
 (function() {
 
     this.toggleCommentLines = function(state, doc, range) {
-        var addedRows = doc.outdentRows(range, "//");
-        if (addedRows == 0) {
-            var addedRows = doc.indentRows(range, "//");
-        };
-        return addedRows;
+        var outdent = true;
+        var outentedRows = [];
+        var re = /^(\s*)\/\//;
+
+        for (var i=range.start.row; i<= range.end.row; i++) {
+            if (!re.test(doc.getLine(i))) {
+                outdent = false;
+                break;
+            }
+        }
+
+        if (outdent) {
+            var deleteRange = new ace.Range(0, 0, 0, 0);
+            for (var i=range.start.row; i<= range.end.row; i++)
+            {
+                var line = doc.getLine(i).replace(re, "$1");
+                deleteRange.start.row = i;
+                deleteRange.end.row = i;
+                deleteRange.end.column = line.length + 2;
+                doc.replace(deleteRange, line);
+            }
+            return -2;
+        }
+        else {
+            return doc.indentRows(range, "//");
+        }
     };
 
     this.getNextLineIndent = function(state, line, tab) {
diff --git a/src/test/ace/TextEditTest.js b/src/test/ace/TextEditTest.js
index f05ef3cc..c31650c9 100644
--- a/src/test/ace/TextEditTest.js
+++ b/src/test/ace/TextEditTest.js
@@ -145,10 +145,29 @@ var TextEditTest = TestCase("TextEditTest",
         editor.toggleCommentLines();
 
         assertEquals(["  abc", "cde"].join("\n"), doc.toString());
+        assertRange(0, 0, 1, 1, editor.getSelectionRange());
+    },
 
-        var selection = editor.getSelectionRange();
-        assertPosition(0, 0, selection.start);
-        assertPosition(1, 1, selection.end);
+    "test: comment lines - if the selection end is at the line start it should stay there": function() {
+        //select down
+        var doc = new ace.Document(["abc", "cde"].join("\n"), new ace.mode.JavaScript());
+        var editor = new ace.Editor(new MockRenderer(), doc);
+
+        editor.moveCursorTo(0, 0);
+        editor.getSelection().selectDown();
+
+        editor.toggleCommentLines();
+        assertRange(0, 2, 1, 0, editor.getSelectionRange());
+
+        // select up
+        var doc = new ace.Document(["abc", "cde"].join("\n"), new ace.mode.JavaScript());
+        var editor = new ace.Editor(new MockRenderer(), doc);
+
+        editor.moveCursorTo(1, 0);
+        editor.getSelection().selectUp();
+
+        editor.toggleCommentLines();
+        assertRange(0, 2, 1, 0, editor.getSelectionRange());
     },
 
     "test: move lines down should select moved lines" : function() {
diff --git a/src/test/ace/mode/JavaScriptTest.js b/src/test/ace/mode/JavaScriptTest.js
index 1a03692d..79f49330 100644
--- a/src/test/ace/mode/JavaScriptTest.js
+++ b/src/test/ace/mode/JavaScriptTest.js
@@ -37,6 +37,14 @@ var JavaScriptTest = new TestCase("mode.JavaScriptTest", {
         assertEquals(["////  abc", "////cde", "//fg"].join("\n"), doc.toString());
     },
 
+    "test: toggle comment on a comment line with leading white space": function() {
+        var doc = new ace.Document(["//cde", "  //fg"]);
+
+        var range = new ace.Range(0, 3, 1, 1);
+        var comment = this.mode.toggleCommentLines("start", doc, range);
+        assertEquals(["cde", "  fg"].join("\n"), doc.toString());
+    },
+
     "test: auto indent after opening brace" : function() {
         assertEquals("  ", this.mode.getNextLineIndent("start", "if () {", "  "));
     },