Fix the case where the browser livelocks if we cannot open a file.

If one tries to upload a file that one doesn't have read access to,
the browser livelocks. It tries to read from the file, gets nothing
but spins forever because it knows that it hasn't finished reading.

To address this, firstly we add a check at stat() time to make sure
that we can read the file. However, this doesn't take care of the case
where the access() call was incorrect, or the permissions have changed
under us. In this case, we replace the missing file with NULs.

BUG=30850

Review URL: http://codereview.chromium.org/541022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@42152 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 32 insertions, 11 deletions

diff --git a/net/base/file_stream_win.cc b/net/base/file_stream_win.cc
index cec6a9d..3119a26 100644
--- a/net/base/file_stream_win.cc
+++ b/net/base/file_stream_win.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2008 The Chromium Authors. All rights reserved.  Use of this
+// 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.
 
@@ -120,16 +120,10 @@ FileStream::FileStream()
       open_flags_(0) {
 }
 
-FileStream::FileStream(base::PlatformFile file, int flags)
-    : file_(file),
-      open_flags_(flags) {
-  // If the file handle is opened with base::PLATFORM_FILE_ASYNC, we need to
-  // make sure we will perform asynchronous File IO to it.
-  if (flags & base::PLATFORM_FILE_ASYNC) {
-    async_context_.reset(new AsyncContext(this));
-    MessageLoopForIO::current()->RegisterIOHandler(file_,
-                                                   async_context_.get());
-  }
+FileStream::FileStream(base::PlatformFile file, int open_flags)
+    : file_(INVALID_HANDLE_VALUE),
+      open_flags_(0) {
+  Open(file, open_flags);
 }
 
 FileStream::~FileStream() {
@@ -147,6 +141,13 @@ void FileStream::Close() {
   }
 }
 
+void FileStream::Release() {
+  if (file_ != INVALID_HANDLE_VALUE)
+    CancelIo(file_);
+  async_context_.reset();
+  file_ = INVALID_HANDLE_VALUE;
+}
+
 int FileStream::Open(const FilePath& path, int open_flags) {
   if (IsOpen()) {
     DLOG(FATAL) << "File is already open!";
@@ -170,6 +171,26 @@ int FileStream::Open(const FilePath& path, int open_flags) {
   return OK;
 }
 
+int FileStream::Open(base::PlatformFile file, int open_flags) {
+  if (IsOpen()) {
+    DLOG(FATAL) << "File is already open!";
+    return ERR_UNEXPECTED;
+  }
+
+  open_flags_ = open_flags;
+  file_ = file;
+
+  // If the file handle is opened with base::PLATFORM_FILE_ASYNC, we need to
+  // make sure we will perform asynchronous File IO to it.
+  if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
+    async_context_.reset(new AsyncContext(this));
+    MessageLoopForIO::current()->RegisterIOHandler(file_,
+                                                   async_context_.get());
+  }
+
+  return OK;
+}
+
 bool FileStream::IsOpen() const {
   return file_ != INVALID_HANDLE_VALUE;
 }