Fix homepage migration for users who never changed their settings.

chrome/browser/prefs/session_startup_pref.cc

 // Copyright (c) 2012 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/prefs/session_startup_pref.h"
 
 #include <string>
 
 #include "base/values.h"
 #include "chrome/browser/net/url_fixer_upper.h"
@@ skipping 24 matching lines @@
 // Converts a SessionStartupPref::Type to an integer written to prefs.
 int TypeToPrefValue(SessionStartupPref::Type type) {
   switch (type) {
     case SessionStartupPref::LAST:     return kPrefValueLast;
     case SessionStartupPref::URLS:     return kPrefValueURLs;
     default:                           return kPrefValueNewTab;
   }
 }
 
 void SetNewURLList(PrefService* prefs) {
-  ListValue new_url_pref_list;
-  StringValue* home_page = new StringValue(prefs->GetString(prefs::kHomePage));
-  new_url_pref_list.Append(home_page);
-  prefs->Set(prefs::kURLsToRestoreOnStartup, new_url_pref_list);
+  if (prefs->IsUserModifiablePreference(prefs::kURLsToRestoreOnStartup)) {
+    ListValue new_url_pref_list;
+    StringValue* home_page =
+        new StringValue(prefs->GetString(prefs::kHomePage));
+    new_url_pref_list.Append(home_page);
+    prefs->Set(prefs::kURLsToRestoreOnStartup, new_url_pref_list);
+  }
 }
 
 void URLListToPref(const base::ListValue* url_list, SessionStartupPref* pref) {
   pref->urls.clear();
   for (size_t i = 0; i < url_list->GetSize(); ++i) {
     Value* value = NULL;
     CHECK(url_list->Get(i, &value));
     std::string url_text;
     if (value->GetAsString(&url_text)) {
       GURL fixed_url = URLFixerUpper::FixupURL(url_text, "");
       pref->urls.push_back(fixed_url);
     }
   }
 }
 
 }  // namespace
 
 // static
 void SessionStartupPref::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterIntegerPref(prefs::kRestoreOnStartup,
                              TypeToPrefValue(GetDefaultStartupType()),
                              PrefService::SYNCABLE_PREF);
   prefs->RegisterListPref(prefs::kURLsToRestoreOnStartup,
                           PrefService::SYNCABLE_PREF);
+  prefs->RegisterBooleanPref(prefs::kRestoreOnStartupMigrated,
+                             false,
+                             PrefService::UNSYNCABLE_PREF);
 }
 
 // static
 SessionStartupPref::Type SessionStartupPref::GetDefaultStartupType() {
 #if defined(OS_CHROMEOS)
   SessionStartupPref::Type type = SessionStartupPref::LAST;
 #else
   SessionStartupPref::Type type = SessionStartupPref::DEFAULT;
 #endif
 
@@ skipping 39 matching lines @@
 
 // static
 SessionStartupPref SessionStartupPref::GetStartupPref(Profile* profile) {
   DCHECK(profile);
   return GetStartupPref(profile->GetPrefs());
 }
 
 // static
 SessionStartupPref SessionStartupPref::GetStartupPref(PrefService* prefs) {
   DCHECK(prefs);
+
+  MigrateIfNecessary(prefs);
+
   SessionStartupPref pref(
       PrefValueToType(prefs->GetInteger(prefs::kRestoreOnStartup)));
 
-  // Migrate from "Open the home page" to "Open the following URLs". If the user
-  // had the "Open the homepage" option selected, then we need to switch them to
-  // "Open the following URLs" and set the list of URLs to a list containing
-  // just the user's homepage.
-  if (pref.type == SessionStartupPref::HOMEPAGE) {
-    prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueURLs);
-    pref.type = SessionStartupPref::URLS;
-    SetNewURLList(prefs);
+  if (pref.type == HOMEPAGE) {
+    // We've already migrated, so the only way this can happen is if
+    // kRestoreOnStartup is controlled by a policy. In that case, act as though
+    // URLS was selected.

[Mattias Nissler (ping if slow), 2012/04/18 11:40:54]

We should change RestoreOnStartupPolicyHandler in
configuration_policy_handler.cc to translate policy to the correct pref then. OK
to do in a follow-up CL though. Can you file a bug and put a reference here?

[Tyler Breisacher (Chromium), 2012/04/18 18:26:03]

http://crbug.com/124027

The patch I just uploaded, I wrote as though that had already been fixed. This
makes it a lot easier to write, of course, but if the "RestoreOnStartup" policy
is set to 0, we hit a NOTREACHED() in browser_init.cc

So it might be better to fix the policy-preference mapping first, and then come
back to this CL.

[Mattias Nissler (ping if slow), 2012/04/19 13:23:17]

Thanks for fixing the policy!

+    pref.type = URLS;
   }
 
   // Always load the urls, even if the pref type isn't URLS. This way the
   // preferences panels can show the user their last choice.
   const ListValue* url_list = prefs->GetList(prefs::kURLsToRestoreOnStartup);
   URLListToPref(url_list, &pref);
 
   return pref;
 }
 
 // static
+void SessionStartupPref::MigrateIfNecessary(PrefService* prefs) {
+  DCHECK(prefs);
+
+  if (!prefs->GetBoolean(prefs::kRestoreOnStartupMigrated)) {
+
+    if (prefs->GetInteger(prefs::kRestoreOnStartup) == kPrefValueHomePage ||
+        (!prefs->HasPrefPath(prefs::kRestoreOnStartup) &&
+         !prefs->GetBoolean(prefs::kHomePageIsNewTabPage))) {
+
+      if (prefs->GetBoolean(prefs::kHomePageIsNewTabPage)) {

[Mattias Nissler (ping if slow), 2012/04/18 11:40:54]

This still breaks if prefs::kHomePageIsNewTabPage is under policy control, in
which case you write the policy-enforced value to user prefs.

[Tyler Breisacher (Chromium), 2012/04/18 18:26:03]

I don't think we change the value of kHomePageIsNewTabPage during the migration.

[Mattias Nissler (ping if slow), 2012/04/19 13:23:17]

What I meant was that the pref value you get in line 169 could actually be not
what the user configured, but what policy enforced. In that case you make a
wrong decision, since you're really meaning to migrate user choice, and not
policy-adjusted user choice.

+        if (prefs->IsUserModifiablePreference(prefs::kRestoreOnStartup))
+          prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueNewTab);
+      } else {
+        if (prefs->IsUserModifiablePreference(prefs::kRestoreOnStartup))
+          prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueURLs);
+        SetNewURLList(prefs);
+      }
+    }
+
+    prefs->SetBoolean(prefs::kRestoreOnStartupMigrated, true);
+  }
+}
+
+// static
 bool SessionStartupPref::TypeIsManaged(PrefService* prefs) {
   DCHECK(prefs);
   const PrefService::Preference* pref_restore =
       prefs->FindPreference(prefs::kRestoreOnStartup);
   DCHECK(pref_restore);
   return pref_restore->IsManaged();
 }
 
 // static
 bool SessionStartupPref::URLsAreManaged(PrefService* prefs) {
@@ skipping 45 matching lines @@
   CHECK(prefs_watcher->GetBackupForPref(
             prefs::kURLsToRestoreOnStartup)->GetAsList(&url_list));
   URLListToPref(url_list, &backup_pref);
 
   return backup_pref;
 }
 
 SessionStartupPref::SessionStartupPref(Type type) : type(type) {}
 
 SessionStartupPref::~SessionStartupPref() {}