Defend against deleting the default search provider when merging duplicate TURLs.

chrome/browser/search_engines/template_url_service.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/search_engines/template_url_service.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/i18n/case_conversion.h"
@@ skipping 1789 matching lines @@
   DCHECK(local_turl);
   DCHECK(change_list);
 
   scoped_ptr<TemplateURL> scoped_sync_turl(sync_turl);
 
   if (scoped_sync_turl->last_modified() > local_turl->last_modified()) {
     // Fully replace local_url with Sync's copy. Note that because use Add
     // rather than ResetTemplateURL, |sync_url| is added with a fresh
     // TemplateURLID. We don't need to sync the new ID back to the server since
     // it's only relevant locally.
-    Remove(local_turl);
-    // Force the local ID to 0 so we can add it.
-    scoped_sync_turl->set_id(0);
-    Add(scoped_sync_turl.release());
+    bool delete_default = (local_turl == GetDefaultSearchProvider());
+    if (delete_default && is_default_search_managed_) {
+      NOTREACHED() << "Tried to delete managed default search provider";
+    } else {
+      if (delete_default)
+        default_search_provider_ = NULL;
+
+      Remove(local_turl);
+
+      // Force the local ID to 0 so we can add it.
+      scoped_sync_turl->set_id(0);
+      TemplateURL* temp = scoped_sync_turl.release();
+      Add(temp);
+      if (delete_default)
+        SetDefaultSearchProvider(temp);
+    }
   } else {
     // Change the local TURL's GUID to the server's GUID and push an update to
     // Sync. This ensures that the rest of local_url's fields are sync'd up to
     // the server, and the next time local_url is synced, it is recognized by
     // having the same GUID.
     ResetTemplateURLGUID(local_turl, sync_turl->sync_guid());
     SyncData sync_data = CreateSyncDataFromTemplateURL(*local_turl);
     change_list->push_back(SyncChange(SyncChange::ACTION_UPDATE, sync_data));
   }
 }
@@ skipping 33 matching lines @@
        i != template_urls->end(); ++i) {
     TemplateURL* template_url = *i;
     DCHECK(template_url);
     if (template_url->sync_guid().empty()) {
       template_url->set_sync_guid(guid::GenerateGUID());
       if (service_.get())
         service_->UpdateKeyword(*template_url);
     }
   }
 }