Protector: string and fix segfault fix on button press.

chrome/browser/protector/default_search_provider_change.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 "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/protector/base_setting_change.h"
 #include "chrome/browser/protector/histograms.h"
@@ skipping 51 matching lines @@
   void OpenSearchEngineSettings();
 
   int64 old_id_;
   int64 new_id_;
   // ID of the search engine that we fall back to if the backup is lost.
   int64 fallback_id_;
   string16 old_name_;
   string16 new_name_;
   // Name of the search engine that we fall back to if the backup is lost.
   string16 fallback_name_;
-  string16 product_name_;
   // Histogram ID of the new search provider.
   int new_histogram_id_;
   // Default search provider set by |Init| for the period until user makes a
   // choice and either |Apply| or |Discard| is performed. Should only be used
   // for comparison with the current default search provider and never
   // dereferenced other than in |Init| because it may be deallocated by
   // TemplateURLService at any time.
   const TemplateURL* default_search_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultSearchProviderChange);
 };
 
 DefaultSearchProviderChange::DefaultSearchProviderChange(
     const TemplateURL* old_url,
     const TemplateURL* new_url)
     : old_id_(0),
       new_id_(0),
       fallback_id_(0),
-      product_name_(l10n_util::GetStringUTF16(IDS_PRODUCT_NAME)),
       new_histogram_id_(GetSearchProviderHistogramID(new_url)),
       default_search_provider_(NULL) {
   if (new_url) {
     new_id_ = new_url->id();
     new_name_ = new_url->short_name();
   }
   if (old_url) {
     old_id_ = old_url->id();
     old_name_ = old_url->short_name();
   }
@@ skipping 16 matching lines @@
     return false;
 
   if (!old_id_ || default_search_provider_->id() != old_id_) {
     // Old settings is lost or invalid, so we had to fall back to one of the
     // prepopulated search engines.
     fallback_id_ = default_search_provider_->id();
     fallback_name_ = default_search_provider_->short_name();
     VLOG(1) << "Fallback to " << fallback_name_;
   }
 
+  // This must be called after the initial |SetDefaultSearchProvider| call
+  // because the latter will remove the observer.
   protector->GetTemplateURLService()->AddObserver(this);
 
   return true;
 }
 
 void DefaultSearchProviderChange::Apply() {
   UMA_HISTOGRAM_ENUMERATION(
       kProtectorHistogramSearchProviderApplied,
       new_histogram_id_,
       kProtectorMaxSearchProviderID);
@@ skipping 30 matching lines @@
 void DefaultSearchProviderChange::OnBeforeRemoved() {
   protector()->GetTemplateURLService()->RemoveObserver(this);
 }
 
 string16 DefaultSearchProviderChange::GetBubbleTitle() const {
   return l10n_util::GetStringUTF16(IDS_SEARCH_ENGINE_CHANGE_TITLE);
 }
 
 string16 DefaultSearchProviderChange::GetBubbleMessage() const {
   if (fallback_name_.empty())
-    return l10n_util::GetStringFUTF16(
-        IDS_SEARCH_ENGINE_CHANGE_MESSAGE, product_name_);
+    return l10n_util::GetStringUTF16(IDS_SEARCH_ENGINE_CHANGE_MESSAGE);
   else
     return l10n_util::GetStringFUTF16(
-        IDS_SEARCH_ENGINE_CHANGE_NO_BACKUP_MESSAGE,
-        product_name_, fallback_name_);
+        IDS_SEARCH_ENGINE_CHANGE_NO_BACKUP_MESSAGE, fallback_name_);
 }
 
 string16 DefaultSearchProviderChange::GetApplyButtonText() const {
   if (new_id_) {
     if (new_id_ == fallback_id_) {
       // Old search engine is lost, the fallback search engine is the same as
       // the new one so no need to show this button.
       return string16();
     }
     if (new_name_.length() > kMaxDisplayedNameLength)
@@ skipping 48 matching lines @@
         url = urls[i];
         break;
       }
     }
   }
   if (!url && allow_fallback) {
     url = url_service->FindNewDefaultSearchProvider();
     DCHECK(url);
   }
   if (url) {
+    // Remove ourselves from the observer list to prevent from catching our own
+    // change. It is safe to do this multiple times or before adding ourselves.
+    url_service->RemoveObserver(this);
     url_service->SetDefaultSearchProvider(url);
     VLOG(1) << "Default search provider set to: " << url->short_name();
+    // No need to re-add observer again because any further changes to the
+    // default search provider are of no interest.
   }
   return url;
 }
 
 void DefaultSearchProviderChange::OpenSearchEngineSettings() {
   protector()->OpenTab(
       GURL(std::string(chrome::kChromeUISettingsURL) +
            chrome::kSearchEnginesSubPage));
 }
 
 BaseSettingChange* CreateDefaultSearchProviderChange(
     const TemplateURL* actual,
     const TemplateURL* backup) {
   return new DefaultSearchProviderChange(backup, actual);
 }
 
 }  // namespace protector