part of fix for 95685 reduce bloat by closing db if a folder is unselected, r=naving (who did part of this patch), sr=sspitzer

mailnews/base/public/nsIMsgFolder.idl

@@ -2,16 +2,31 @@
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: NPL 1.1/GPL 2.0/LGPL 2.1
  *
+<<<<<<< nsIMsgFolder.idl
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+=======
  * The contents of this file are subject to the Netscape Public License
  * Version 1.1 (the "License"); you may not use this file except in
  * compliance with the License. You may obtain a copy of the License at
  * http://www.mozilla.org/NPL/
+>>>>>>> 1.131
  *
+<<<<<<< nsIMsgFolder.idl
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+=======
  * Software distributed under the License is distributed on an "AS IS" basis,
  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  * for the specific language governing rights and limitations under the
  * License.
  *
+>>>>>>> 1.131
  * The Original Code is mozilla.org code.
  *
  * The Initial Developer of the Original Code is 
@@ -361,6 +376,7 @@ const nsMsgBiffState nsMsgBiffState_Unknown = 2; // We dunno whether there is ne
 	void markMessagesFlagged(in nsISupportsArray messages, in boolean markFlagged);
 	void markThreadRead(in nsIMsgThread thread);
 	nsIMsgDatabase getMsgDatabase(in nsIMsgWindow msgWindow);
+	void setMsgDatabase (in nsIMsgDatabase msgDatabase);
 	nsIMsgDatabase getDBFolderInfoAndDB(out nsIDBFolderInfo folderInfo);
 	nsIMsgDBHdr GetMessageHeader(in nsMsgKey msgKey);
 

mailnews/base/resources/content/commandglue.js

@@ -289,6 +289,12 @@ function RerootFolder(uri, newFolder, viewType, viewFlags, sortType, sortOrder)
 
   // now create the db view, which will sort it.
   CreateDBView(newFolder, viewType, viewFlags, sortType, sortOrder);
+  if (oldFolder)
+  {
+    if (!IsSpecialFolder(oldFolder, MSG_FOLDER_FLAG_INBOX))
+      if (oldFolder.URI != newFolder.URI)
+        oldFolder.setMsgDatabase(null);
+  }
   // that should have initialized gDBView, now re-root the thread pane
   var outlinerView = gDBView.QueryInterface(Components.interfaces.nsIOutlinerView);
   if (outlinerView)
@@ -671,6 +677,7 @@ function FolderPaneSelectionChange()
                   sortOrder = dbFolderInfo.sortOrder;
                   viewFlags = dbFolderInfo.viewFlags;
                   viewType = dbFolderInfo.viewType;
+                  msgDatabase = null;
                 }
               }
               catch (ex)

mailnews/base/util/nsMsgDBFolder.cpp

@@ -647,6 +647,20 @@ nsMsgDBFolder::GetMsgDatabase(nsIMsgWindow *aMsgWindow,
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsMsgDBFolder::SetMsgDatabase(nsIMsgDatabase *aMsgDatabase)
+{
+  if (mDatabase)
+  {
+    mDatabase->RemoveListener(this);
+    mDatabase->ClearCachedHdrs();
+  }
+  mDatabase = aMsgDatabase;
+  if (aMsgDatabase)
+    aMsgDatabase->AddListener(this);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsMsgDBFolder::OnReadChanged(nsIDBChangeListener * aInstigator)
 {

mailnews/base/util/nsMsgDBFolder.h

@@ -78,6 +78,7 @@ public:
 
   NS_IMETHOD GetMsgDatabase(nsIMsgWindow *aMsgWindow,
                             nsIMsgDatabase** aMsgDatabase);
+  NS_IMETHOD SetMsgDatabase(nsIMsgDatabase *msgDatabase);
 
   NS_DECL_ISUPPORTS_INHERITED