fix 266536 handling of out of date local folder summary files, sr=mscott

mail/base/content/commandglue.js

@@ -162,7 +162,7 @@ function UpdateMailToolbar(caller)
 
 function ChangeFolderByURI(uri, viewType, viewFlags, sortType, sortOrder)
 {
-  //dump("In ChangeFolderByURI uri = " + uri + " sortType = " + sortType + "\n");
+  viewDebug("In ChangeFolderByURI uri = " + uri + " sortType = " + sortType + "\n");
   if (uri == gCurrentLoadingFolderURI)
     return;
 
@@ -284,7 +284,25 @@ function isNewsURI(uri)
 
 function RerootFolder(uri, newFolder, viewType, viewFlags, sortType, sortOrder)
 {
-  //dump("In reroot folder, sortType = " +  sortType + "viewType = " + viewType + "\n");
+  viewDebug("In reroot folder, sortType = " +  sortType + "viewType = " + viewType + "\n");
+
+  if (sortType == 0)
+  {
+    try
+    {
+      var msgdb = newFolder.getMsgDatabase(msgWindow);
+      var dbFolderInfo = msgdb.dBFolderInfo;
+      sortType = dbFolderInfo.sortType;
+      sortOrder = dbFolderInfo.sortOrder;
+      viewFlags = dbFolderInfo.viewFlags;
+      viewType = dbFolderInfo.viewType;
+      dbFolderInfo = null;
+    }
+    catch(ex)
+    {
+      dump("invalid db in RerootFolder: " + ex + "\n");
+    }
+  }
 
   // workaround for #39655
   gFolderJustSwitched = true;
@@ -650,6 +668,10 @@ function CreateBareDBView(originalView, msgFolder, viewType, viewFlags, sortType
           break;
       case nsMsgViewType.eShowAllThreads:
       default:
+          if (sortType == nsMsgViewSortType.byThread || sortType == nsMsgViewSortType.byId
+            || sortType == nsMsgViewSortType.byNone)
+            viewFlags &= ~nsMsgViewFlagsType.kGroupBySort;
+
           if (viewFlags & nsMsgViewFlagsType.kGroupBySort)
             dbviewContractId += "group";
           else
@@ -1128,7 +1150,7 @@ function CreateGroupedSearchTerms(searchTermsArray)
   return searchTermsArrayForQS;
 }
 
-var gViewDebug = false;
+var gViewDebug = true;
 
 function viewDebug(str)
 {

mail/base/content/msgHdrViewOverlay.js

@@ -273,7 +273,7 @@ const MsgHdrViewObserver =
 var messageHeaderSink = {
     onStartHeaders: function()
     {
-
+      mSaveHdr = null;
       // clear out any pending collected address timers...
       if (gCollectAddressTimer)
       {