Revert 138554 - Prevent zero-length items from being appended to a blob.

content/common/fileapi/webblobregistry_impl.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 "content/common/fileapi/webblobregistry_impl.h"
 
 #include "base/memory/ref_counted.h"
 #include "base/shared_memory.h"
 #include "content/common/child_thread.h"
 #include "content/common/fileapi/webblob_messages.h"
@@ skipping 21 matching lines @@
 
   child_thread_->Send(new BlobHostMsg_StartBuildingBlob(url));
   size_t i = 0;
   WebBlobData::Item data_item;
   while (data.itemAt(i++, data_item)) {
     webkit_blob::BlobData::Item item;
     switch (data_item.type) {
       case WebBlobData::Item::TypeData: {
         // WebBlobData does not allow partial data items.
         DCHECK(!data_item.offset && data_item.length == -1);
-        if (data_item.data.size() == 0)
-          break;
         if (data_item.data.size() < kLargeThresholdBytes) {
           item.SetToData(data_item.data.data(), data_item.data.size());
           child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
         } else {
           // We handle larger amounts of data via SharedMemory instead of
           // writing it directly to the IPC channel.
           size_t data_size = data_item.data.size();
           const char* data_ptr = data_item.data.data();
           size_t shared_memory_size = std::min(
               data_size, kMaxSharedMemoryBytes);
           scoped_ptr<base::SharedMemory> shared_memory(
               child_thread_->AllocateSharedMemory(shared_memory_size));
           CHECK(shared_memory.get());
           while (data_size) {
             size_t chunk_size = std::min(data_size, shared_memory_size);
             memcpy(shared_memory->memory(), data_ptr, chunk_size);
             child_thread_->Send(new BlobHostMsg_SyncAppendSharedMemory(
                 url, shared_memory->handle(), chunk_size));
             data_size -= chunk_size;
             data_ptr += chunk_size;
           }
         }
         break;
       }
       case WebBlobData::Item::TypeFile:
-        if (data_item.length) {
-          item.SetToFile(
-              webkit_glue::WebStringToFilePath(data_item.filePath),
-              static_cast<uint64>(data_item.offset),
-              static_cast<uint64>(data_item.length),
-              base::Time::FromDoubleT(data_item.expectedModificationTime));
-          child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
-        }
+        item.SetToFile(
+            webkit_glue::WebStringToFilePath(data_item.filePath),
+            static_cast<uint64>(data_item.offset),
+            static_cast<uint64>(data_item.length),
+            base::Time::FromDoubleT(data_item.expectedModificationTime));
+        child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
         break;
       case WebBlobData::Item::TypeBlob:
         if (data_item.length) {
           item.SetToBlob(
               data_item.blobURL,
               static_cast<uint64>(data_item.offset),
               static_cast<uint64>(data_item.length));
-          child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
         }
+        child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
         break;
       default:
         NOTREACHED();
     }
   }
   child_thread_->Send(new BlobHostMsg_FinishBuildingBlob(
       url, data.contentType().utf8().data()));
 }
 
 void WebBlobRegistryImpl::registerBlobURL(
     const WebURL& url, const WebURL& src_url) {
   child_thread_->Send(new BlobHostMsg_CloneBlob(url, src_url));
 }
 
 void WebBlobRegistryImpl::unregisterBlobURL(const WebURL& url) {
   child_thread_->Send(new BlobHostMsg_RemoveBlob(url));
 }