filesystem.cpp: __std_fs_write_reparse_data_buffer() should use the size of the buffer, not buffer pointer

[SiliconA-Z]

No description provided.

[StephanTLavavej]

This certainly appears to be a bug, after looking into how FSCTL_GET_REPARSE_POINT and FSCTL_SET_REPARSE_POINT work. This codepath is used in a single place, when copying a junction. I'll need to manually exercise this scenario (automated test coverage could potentially be problematic).

[StephanTLavavej]

We don't think this fix is correct, sizeof(*_Buffer) contains a "fake" array element.

[Morddin]

After a quick search on the internet, it seems that sizeof(_Buffer) should be replaced with REPARSE_DATA_BUFFER_HEADER_SIZE.

REPARSE_DATA_BUFFER_HEADER_SIZE is defined in the Windows Driver Kit as:

#define REPARSE_DATA_BUFFER_HEADER_SIZE   UFIELD_OFFSET(REPARSE_DATA_BUFFER, GenericReparseBuffer)

Its value is 8.

[StephanTLavavej]

Superseded by #6064, thanks everyone.