From 949507c3feeea41d5559b82c2456300c2afe5f40 Mon Sep 17 00:00:00 2001
From: Hamish Friedlander <hamish@silverstripe.com>
Date: Wed, 29 Aug 2012 14:48:23 +1200
Subject: [PATCH 1/2] NEW Add warning if viewed SiteTree object class is
 obsolete

---
 code/model/SiteTree.php | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/code/model/SiteTree.php b/code/model/SiteTree.php
index b4a25ef7..da9bcf59 100644
--- a/code/model/SiteTree.php
+++ b/code/model/SiteTree.php
@@ -1803,7 +1803,7 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		if($this->HasBrokenLink || $this->HasBrokenFile) {
 			$statusMessage[] = _t('SiteTree.HASBROKENLINKS', "This page has broken links.");
 		}
-		
+
 		$dependentNote = '';
 		$dependentTable = new LiteralField('DependentNote', '<p></p>');
 		
@@ -1877,6 +1877,20 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		
 		$tabMain->setTitle(_t('SiteTree.TABCONTENT', "Main Content"));
 
+		if($this->ObsoleteClassName) {
+			$obsoleteWarning = _t(
+				'SiteTree.OBSOLETECLASS',
+				"This page is of obsolete type {type}. Saving will reset it's type and you may lose data",
+				array('type' => $this->ObsoleteClassName)
+			);
+
+			$fields->addFieldToTab(
+				"Root.Main",
+				new LiteralField("ObsoleteWarningHeader", "<p class=\"message warning\">$obsoleteWarning</p>"),
+				"Title"
+			);
+		}
+
 		if(file_exists(BASE_PATH . '/install.php')) {
 			$fields->addFieldToTab("Root.Main", new LiteralField("InstallWarningHeader", 
 				"<p class=\"message warning\">" . _t("SiteTree.REMOVE_INSTALL_WARNING", 

From d9243cddde050c9d1d65533b92011dc0b5ce7fd1 Mon Sep 17 00:00:00 2001
From: Hamish Friedlander <hamish@silverstripe.com>
Date: Wed, 29 Aug 2012 16:17:17 +1200
Subject: [PATCH 2/2] FIX Pages with obsolete class shouldnt do first
 versionless write

---
 code/controllers/CMSMain.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/controllers/CMSMain.php b/code/controllers/CMSMain.php
index dccb354c..bdd5fa2a 100644
--- a/code/controllers/CMSMain.php
+++ b/code/controllers/CMSMain.php
@@ -783,7 +783,7 @@ class CMSMain extends LeftAndMain implements CurrentPageIdentifier, PermissionPr
 		$record->HasBrokenLink = 0;
 		$record->HasBrokenFile = 0;
 
-		$record->writeWithoutVersion();
+		if (!$record->ObsoleteClassName) $record->writeWithoutVersion();
 
 		// Update the class instance if necessary
 		if(isset($data['ClassName']) && $data['ClassName'] != $record->ClassName) {