[sql] Recover Favicons v5 databases, with more recovery automation.

sql/connection_unittest.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 "base/bind.h"
 #include "base/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
 #include "sql/connection.h"
 #include "sql/meta_table.h"
 #include "sql/statement.h"
 #include "sql/test/error_callback_support.h"
 #include "sql/test/scoped_error_ignorer.h"
+#include "sql/test/test_helpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/sqlite/sqlite3.h"
 
 namespace {
 
 // Helper to return the count of items in sqlite_master.  Return -1 in
 // case of error.
 int SqliteMasterCount(sql::Connection* db) {
   const char* kMasterCount = "SELECT COUNT(*) FROM sqlite_master";
   sql::Statement s(db->GetUniqueStatement(kMasterCount));
@@ skipping 471 matching lines @@
 
   // Now empty, the open should succeed with an empty database.
   EXPECT_TRUE(db().Open(db_path()));
   EXPECT_EQ(0, SqliteMasterCount(&db()));
 }
 
 // Test that a callback from Open() can raze the database.  This is
 // essential for cases where the Open() can fail entirely, so the
 // Raze() cannot happen later.  Additionally test that when the
 // callback does this during Open(), the open is retried and succeeds.
-//
-// Most corruptions seen in the wild seem to happen when two pages in
-// the database were not written transactionally (the transaction
-// changed both, but one wasn't successfully written for some reason).
-// A special case of that is when the header indicates that the
-// database contains more pages than are in the file.  This breaks
-// things at a very basic level, verify that Raze() can handle it.
 TEST_F(SQLConnectionTest, RazeCallbackReopen) {
   const char* kCreateSql = "CREATE TABLE foo (id INTEGER PRIMARY KEY, value)";
   ASSERT_TRUE(db().Execute(kCreateSql));
   ASSERT_EQ(1, SqliteMasterCount(&db()));
-  int page_size = 0;
-  {
-    sql::Statement s(db().GetUniqueStatement("PRAGMA page_size"));
-    ASSERT_TRUE(s.Step());
-    page_size = s.ColumnInt(0);
-  }
   db().Close();
 
-  // Trim a single page from the end of the file.
-  {
-    file_util::ScopedFILE file(file_util::OpenFile(db_path(), "rb+"));
-    ASSERT_TRUE(file.get() != NULL);
-    ASSERT_EQ(0, fseek(file.get(), -page_size, SEEK_END));
-    ASSERT_TRUE(file_util::TruncateFile(file.get()));
-  }
+  // Corrupt the database so that nothing works, including PRAGMAs.
+  ASSERT_TRUE(sql::test::CorruptSizeInHeader(db_path()));
 
   // Open() will succeed, even though the PRAGMA calls within will
   // fail with SQLITE_CORRUPT, as will this PRAGMA.
   {
     sql::ScopedErrorIgnorer ignore_errors;
     ignore_errors.IgnoreError(SQLITE_CORRUPT);
     ASSERT_TRUE(db().Open(db_path()));
     ASSERT_FALSE(db().Execute("PRAGMA auto_vacuum"));
     db().Close();
     ASSERT_TRUE(ignore_errors.CheckIgnoredErrors());
@@ skipping 292 matching lines @@
   }
 
   // Detach succeeds outside of a transaction.
   db().RollbackTransaction();
   EXPECT_TRUE(db().DetachDatabase(kAttachmentPoint));
 
   EXPECT_FALSE(db().IsSQLValid("SELECT count(*) from other.bar"));
 }
 
 }  // namespace