1 files changed, 37 insertions, 9 deletions

diff --git a/chrome/browser/history/archived_database.cc b/chrome/browser/history/archived_database.cc
index 19f6436..40ba38b 100644
--- a/chrome/browser/history/archived_database.cc
+++ b/chrome/browser/history/archived_database.cc
@@ -34,7 +34,7 @@ namespace history {
 
 namespace {
 
-static const int kDatabaseVersion = 1;
+static const int kCurrentVersionNumber = 2;
 
 }  // namespace
 
@@ -73,15 +73,8 @@ bool ArchivedDatabase::Init(const std::wstring& file_name) {
   BeginTransaction();
 
   // Version check.
-  if (!meta_table_.Init(std::string(), kDatabaseVersion, db_))
+  if (!meta_table_.Init(std::string(), kCurrentVersionNumber, db_))
     return false;
-  if (meta_table_.GetCompatibleVersionNumber() > kDatabaseVersion) {
-    // We ignore this error and just run without the database. Normally, if
-    // the user is running two versions, the main history DB will give a
-    // warning about a version from the future.
-    LOG(WARNING) << "Archived database is a future version.";
-    return false;
-  }
 
   // Create the tables.
   if (!CreateURLTable(false) || !InitVisitTable() ||
@@ -89,6 +82,9 @@ bool ArchivedDatabase::Init(const std::wstring& file_name) {
     return false;
   CreateMainURLIndex();
 
+  if (EnsureCurrentVersion() != INIT_OK)
+    return false;
+
   // Succeeded: keep the DB open by detaching the auto-closer.
   scoper.Detach();
   db_closer_.Attach(&db_, &statement_cache_);
@@ -123,4 +119,36 @@ SqliteStatementCache& ArchivedDatabase::GetStatementCache() {
   return *statement_cache_;
 }
 
+// Migration -------------------------------------------------------------------
+
+InitStatus ArchivedDatabase::EnsureCurrentVersion() {
+  // We can't read databases newer than we were designed for.
+  if (meta_table_.GetCompatibleVersionNumber() > kCurrentVersionNumber)
+    return INIT_TOO_NEW;
+
+  // NOTICE: If you are changing structures for things shared with the archived
+  // history file like URLs, visits, or downloads, that will need migration as
+  // well. Instead of putting such migration code in this class, it should be
+  // in the corresponding file (url_database.cc, etc.) and called from here and
+  // from the archived_database.cc.
+
+  // When the version is too old, we just try to continue anyway, there should
+  // not be a released product that makes a database too old for us to handle.
+  int cur_version = meta_table_.GetVersionNumber();
+
+  // Put migration code here
+
+  if (cur_version == 1) {
+    if (!DropStarredIDFromURLs())
+      return INIT_FAILURE;
+    cur_version = 2;
+    meta_table_.SetVersionNumber(cur_version);
+    meta_table_.SetCompatibleVersionNumber(cur_version);
+  }
+
+  LOG_IF(WARNING, cur_version < kCurrentVersionNumber) <<
+      "Archived database version " << cur_version << " is too old to handle.";
+
+  return INIT_OK;
+}
 }  // namespace history