[sql] WebSQL xGetLastError() can be called with null buffer.

third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteFileSystemPosix.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 310 matching lines @@
 int chromiumSleep(sqlite3_vfs* vfs, int microseconds) {
   sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
   return wrappedVfs->xSleep(wrappedVfs, microseconds);
 }
 
 int chromiumCurrentTime(sqlite3_vfs* vfs, double* prNow) {
   sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
   return wrappedVfs->xCurrentTime(wrappedVfs, prNow);
 }
 
-int chromiumGetLastError(sqlite3_vfs* vfs, int e, char* s) {
-  // xGetLastError() has never been used by SQLite.  The implementation in
-  // os_win.c indicates this is a reasonable implementation.
-  *s = '\0';
+int chromiumGetLastError(sqlite3_vfs* vfs, int nBuf, char* zBuf) {

[michaeln, 2017/03/23 20:36:33]

lgtm

+  if (nBuf && zBuf)
+    *zBuf = '\0';
   return 0;
 }
 
 }  // namespace
 
 void SQLiteFileSystem::registerSQLiteVFS() {
   sqlite3_vfs* wrappedVfs = sqlite3_vfs_find("unix");
 
   // These are implemented by delegating to |wrappedVfs|.
   // TODO(shess): Implement local versions.
@@ skipping 16 matching lines @@
                                      chromiumDlSym,
                                      chromiumDlClose,
                                      chromiumRandomness,
                                      chromiumSleep,
                                      chromiumCurrentTime,
                                      chromiumGetLastError};
   sqlite3_vfs_register(&chromium_vfs, 0);
 }
 
 }  // namespace blink