[FileAPI] Check Platform availablity before using it in DOMFileSystem

Source/modules/filesystem/DOMFileSystemBase.cpp

 /*
  * Copyright (C) 2010 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 55 matching lines @@
     , m_clonable(false)
 {
 }
 
 DOMFileSystemBase::~DOMFileSystemBase()
 {
 }
 
 blink::WebFileSystem* DOMFileSystemBase::fileSystem() const
 {
-    return blink::Platform::current()->fileSystem();
+    blink::Platform* platform = blink::Platform::current();
+    if (!platform)
+        return nullptr;
+    return platform->fileSystem();
 }
 
 SecurityOrigin* DOMFileSystemBase::securityOrigin() const
 {
     return m_context->securityOrigin();
 }
 
 bool DOMFileSystemBase::isValidType(FileSystemType type)
 {
     return type == FileSystemTypeTemporary || type == FileSystemTypePersistent || type == FileSystemTypeIsolated || type == FileSystemTypeExternal;
@@ skipping 93 matching lines @@
     if (pathPrefix == externalPathPrefix) {
         type = FileSystemTypeExternal;
         return true;
     }
 
     return false;
 }
 
 void DOMFileSystemBase::getMetadata(const EntryBase* entry, PassOwnPtr<MetadataCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     OwnPtr<AsyncFileSystemCallbacks> callbacks(MetadataCallbacks::create(successCallback, errorCallback, m_context, this));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
     fileSystem()->readMetadata(createFileSystemURL(entry), callbacks.release());
 }
 
 static bool verifyAndGetDestinationPathForCopyOrMove(const EntryBase* source, EntryBase* parent, const String& newName, String& destinationPath)
 {
     ASSERT(source);
 
     if (!parent || !parent->isDirectory())
@@ skipping 16 matching lines @@
     if (!newName.isEmpty())
         destinationPath = DOMFilePath::append(destinationPath, newName);
     else
         destinationPath = DOMFilePath::append(destinationPath, source->name());
 
     return true;
 }
 
 void DOMFileSystemBase::move(const EntryBase* source, EntryBase* parent, const String& newName, PassOwnPtr<EntryCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     String destinationPath;
     if (!verifyAndGetDestinationPathForCopyOrMove(source, parent, newName, destinationPath)) {
         reportError(errorCallback, FileError::create(FileError::INVALID_MODIFICATION_ERR));
         return;
     }
 
     OwnPtr<AsyncFileSystemCallbacks> callbacks(EntryCallbacks::create(successCallback, errorCallback, m_context, parent->filesystem(), destinationPath, source->isDirectory()));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
 
     fileSystem()->move(createFileSystemURL(source), parent->filesystem()->createFileSystemURL(destinationPath), callbacks.release());
 }
 
 void DOMFileSystemBase::copy(const EntryBase* source, EntryBase* parent, const String& newName, PassOwnPtr<EntryCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     String destinationPath;
     if (!verifyAndGetDestinationPathForCopyOrMove(source, parent, newName, destinationPath)) {
         reportError(errorCallback, FileError::create(FileError::INVALID_MODIFICATION_ERR));
         return;
     }
 
     OwnPtr<AsyncFileSystemCallbacks> callbacks(EntryCallbacks::create(successCallback, errorCallback, m_context, parent->filesystem(), destinationPath, source->isDirectory()));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
 
     fileSystem()->copy(createFileSystemURL(source), parent->filesystem()->createFileSystemURL(destinationPath), callbacks.release());
 }
 
 void DOMFileSystemBase::remove(const EntryBase* entry, PassOwnPtr<VoidCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     ASSERT(entry);
     // We don't allow calling remove() on the root directory.
     if (entry->fullPath() == String(DOMFilePath::root)) {
         reportError(errorCallback, FileError::create(FileError::INVALID_MODIFICATION_ERR));
         return;
     }
 
     OwnPtr<AsyncFileSystemCallbacks> callbacks(VoidCallbacks::create(successCallback, errorCallback, m_context, this));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
 
     fileSystem()->remove(createFileSystemURL(entry), callbacks.release());
 }
 
 void DOMFileSystemBase::removeRecursively(const EntryBase* entry, PassOwnPtr<VoidCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     ASSERT(entry && entry->isDirectory());
     // We don't allow calling remove() on the root directory.
     if (entry->fullPath() == String(DOMFilePath::root)) {
         reportError(errorCallback, FileError::create(FileError::INVALID_MODIFICATION_ERR));
         return;
     }
 
     OwnPtr<AsyncFileSystemCallbacks> callbacks(VoidCallbacks::create(successCallback, errorCallback, m_context, this));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
 
     fileSystem()->removeRecursively(createFileSystemURL(entry), callbacks.release());
 }
 
 void DOMFileSystemBase::getParent(const EntryBase* entry, PassOwnPtr<EntryCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     ASSERT(entry);
     String path = DOMFilePath::getDirectory(entry->fullPath());
+
     fileSystem()->directoryExists(createFileSystemURL(path), EntryCallbacks::create(successCallback, errorCallback, m_context, this, path, true));
 }
 
 void DOMFileSystemBase::getFile(const EntryBase* entry, const String& path, const FileSystemFlags& flags, PassOwnPtr<EntryCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     String absolutePath;
     if (!pathToAbsolutePath(m_type, entry, path, absolutePath)) {
         reportError(errorCallback, FileError::create(FileError::INVALID_MODIFICATION_ERR));
         return;
     }
 
     OwnPtr<AsyncFileSystemCallbacks> callbacks(EntryCallbacks::create(successCallback, errorCallback, m_context, this, absolutePath, false));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
 
     if (flags.create)
         fileSystem()->createFile(createFileSystemURL(absolutePath), flags.exclusive, callbacks.release());
     else
         fileSystem()->fileExists(createFileSystemURL(absolutePath), callbacks.release());
 }
 
 void DOMFileSystemBase::getDirectory(const EntryBase* entry, const String& path, const FileSystemFlags& flags, PassOwnPtr<EntryCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return;
+    }
+
     String absolutePath;
     if (!pathToAbsolutePath(m_type, entry, path, absolutePath)) {
         reportError(errorCallback, FileError::create(FileError::INVALID_MODIFICATION_ERR));
         return;
     }
 
     OwnPtr<AsyncFileSystemCallbacks> callbacks(EntryCallbacks::create(successCallback, errorCallback, m_context, this, absolutePath, true));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
 
     if (flags.create)
         fileSystem()->createDirectory(createFileSystemURL(absolutePath), flags.exclusive, callbacks.release());
     else
         fileSystem()->directoryExists(createFileSystemURL(absolutePath), callbacks.release());
 }
 
 int DOMFileSystemBase::readDirectory(DirectoryReaderBase* reader, const String& path, PassOwnPtr<EntriesCallback> successCallback, PassOwnPtr<ErrorCallback> errorCallback, SynchronousType synchronousType)
 {
+    if (!fileSystem()) {
+        reportError(errorCallback, FileError::create(FileError::ABORT_ERR));
+        return 0;
+    }
+
     ASSERT(DOMFilePath::isAbsolute(path));
 
     OwnPtr<AsyncFileSystemCallbacks> callbacks(EntriesCallbacks::create(successCallback, errorCallback, m_context, reader, path));
     callbacks->setShouldBlockUntilCompletion(synchronousType == Synchronous);
 
     return fileSystem()->readDirectory(createFileSystemURL(path), callbacks.release());
 }
 
 bool DOMFileSystemBase::waitForAdditionalResult(int callbacksId)
 {
+    if (!fileSystem())
+        return false;
     return fileSystem()->waitForAdditionalResult(callbacksId);
 }
 
 } // namespace blink