sqlite_utils: don't dereference an empty vector.

chrome/common/sqlite_utils.cc

 // Copyright (c) 2010 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/common/sqlite_utils.h"
 
 #include <list>
 
 #include "base/at_exit.h"
 #include "base/file_path.h"
@@ skipping 305 matching lines @@
   return sqlite3_db_handle(stmt_);
 }
 
 int SQLStatement::bind_parameter_count() {
   DCHECK(stmt_);
   return sqlite3_bind_parameter_count(stmt_);
 }
 
 int SQLStatement::bind_blob(int index, std::vector<unsigned char>* blob) {
   if (blob) {
-    const void* value = &(*blob)[0];
+    const void* value = blob->empty() ? NULL : &(*blob)[0];
     int len = static_cast<int>(blob->size());
     return bind_blob(index, value, len);
   } else {
     return bind_null(index);
   }
 }
 
 int SQLStatement::bind_blob(int index, const void* value, int value_len) {
    return bind_blob(index, value, value_len, SQLITE_TRANSIENT);
 }
@@ skipping 170 matching lines @@
   return wstr;
 }
 
 #if defined(USE_SYSTEM_SQLITE)
 // This function is a local change to sqlite3 which doesn't exist when one is
 // using the system sqlite library. Thus, we stub it out here.
 int sqlite3Preload(sqlite3* db) {
   return 0;
 }
 #endif