Bug #371629 --> when changing the sort column, we weren't always remove the sortdirection attribute on the other tree columns. r=neil

mail/base/content/SearchDialog.xul

@@ -139,7 +139,7 @@
               context="threadPaneContext"
               onkeypress="ThreadPaneKeyPress(event);"
               onselect="ThreadPaneSelectionChanged();">
-          <treecols pickertooltiptext="&columnChooser.tooltip;">
+          <treecols id="threadCols" pickertooltiptext="&columnChooser.tooltip;">
             <treecol id="threadCol" persist="hidden ordinal" fixed="true" cycler="true"
                      class="treecol-image threadColumnHeader" currentView="unthreaded"
                      label="&threadColumn.label;" tooltiptext="&threadColumn.tooltip;"/>

mailnews/base/resources/content/threadPane.js

@@ -415,6 +415,11 @@ function groupedBySortUsingDummyRow()
 
 function UpdateSortIndicators(sortType, sortOrder)
 {
+  // Remove the sort indicator from all the columns
+  var treeColumns = document.getElementById('threadCols').childNodes;
+  for (var i = 0; i < treeColumns.length; i++)
+    treeColumns(i).removeAttribute('sortDirection');
+
   // show the twisties if the view is threaded
   var threadCol = document.getElementById("threadCol");
   var sortedColumn;
@@ -456,12 +461,6 @@ function UpdateSortIndicators(sortType, sortOrder)
     currCol.removeAttribute("primary");
   }
 
-  // remove the sort indicator from all the columns
-  while (currCol) {
-    currCol.removeAttribute("sortDirection");
-    currCol = currCol.nextSibling;
-  }
-
   if (sortedColumn) {
     if (sortOrder == nsMsgViewSortOrder.ascending) {
       sortedColumn.setAttribute("sortDirection","ascending");

mailnews/base/resources/content/threadPane.xul

@@ -53,7 +53,7 @@
     class="plain focusring" disableKeyNavigation="true" lastfoldersent="false" noattachcol="true"
     onkeypress="ThreadPaneKeyPress(event);"
     onselect="ThreadPaneSelectionChanged();">
-  <treecols pickertooltiptext="&columnChooser.tooltip;">
+  <treecols id="threadCols" pickertooltiptext="&columnChooser.tooltip;">
     <treecol id="threadCol" persist="hidden ordinal" fixed="true" cycler="true" class="treecol-image threadColumnHeader" currentView="unthreaded"
              label="&threadColumn.label;" tooltiptext="&threadColumn.tooltip;"/>
     <splitter class="tree-splitter"/>