[update_engine] Fix file creation mask to be 0600

split_file_writer.cc

 // Copyright (c) 2010 The Chromium OS 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 "update_engine/split_file_writer.h"
 #include <algorithm>
 
 using std::min;
 
 namespace chromeos_update_engine {
@@ skipping 25 matching lines @@
   if (rc != static_cast<int>(count)) {
     LOG(ERROR) << "Not all bytes successfully written to file.";
     return -EIO;
   }
   return rc;
 }
 }
 
 ssize_t SplitFileWriter::Write(const void* bytes, size_t count) {
   const size_t original_count = count;
-  
+
   // This first block is trying to read the first sizeof(uint64_t)
   // bytes, which are the number of bytes that should be written
   // to the first FileWriter.
   if (bytes_received_ < static_cast<off_t>(sizeof(uint64_t))) {
     // Write more to the initial buffer
     size_t bytes_to_copy = min(static_cast<off_t>(count),
                                static_cast<off_t>(sizeof(first_length_buf_)) -
                                bytes_received_);
     memcpy(&first_length_buf_[bytes_received_], bytes, bytes_to_copy);
     bytes_received_ += bytes_to_copy;
@@ skipping 14 matching lines @@
   }
   CHECK_GE(bytes_received_, static_cast<off_t>(sizeof(uint64_t)));
 
   // This block of code is writing to the first FileWriter.
   if (bytes_received_ - static_cast<off_t>(sizeof(uint64_t)) < first_length_) {
     // Write to first FileWriter
     size_t bytes_to_write = min(
         first_length_ -
         (bytes_received_ - static_cast<off_t>(sizeof(uint64_t))),
         static_cast<off_t>(count));
-      
+
     int rc = PerformWrite(first_file_writer_, bytes, bytes_to_write);
     if (rc != static_cast<int>(bytes_to_write))
       return rc;
-    
+
     bytes_received_ += bytes_to_write;
     count -= bytes_to_write;
     bytes = static_cast<const void*>(
         static_cast<const char*>(bytes) + bytes_to_write);
     if (count == 0)
       return original_count;
   }
 
   CHECK_GE(static_cast<off_t>(bytes_received_),
            first_length_ + static_cast<off_t>(sizeof(uint64_t)));
   // Write to second FileWriter
   int rc = PerformWrite(second_file_writer_, bytes, count);
   if (rc != static_cast<int>(count))
     return rc;
   return original_count;
 }
 
 int SplitFileWriter::Close() {
   int first_result = first_file_writer_->Close();
   if (first_result < 0)
     LOG(ERROR) << "Error Close()ing first file.";
   int second_result = second_file_writer_->Close();
   if (second_result < 0)
     LOG(ERROR) << "Error Close()ing second file.";
   // Return error if either had returned error.
   return second_result < 0 ? second_result : first_result;
 }
 
 }  // namespace chromeos_update_engine