Quoting Kirk Allan (2015-11-09 15:49:05)
> For append file open modes, use FILE_APPEND_DATA for the desired access for
> writing at the end of the file.
>
> Signed-off-by: Kirk Allan <kal...@suse.com>
> ---
> qga/commands-win32.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index a5306e7..0a23b9b 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -70,16 +70,16 @@ static OpenFlags guest_file_open_modes[] = {
> {"rb", GENERIC_READ, OPEN_EXISTING},
> {"w", GENERIC_WRITE, CREATE_ALWAYS},
> {"wb", GENERIC_WRITE, CREATE_ALWAYS},
> - {"a", GENERIC_WRITE, OPEN_ALWAYS },
> + {"a", FILE_APPEND_DATA, OPEN_ALWAYS },
> {"r+", GENERIC_WRITE|GENERIC_READ, OPEN_EXISTING},
> {"rb+", GENERIC_WRITE|GENERIC_READ, OPEN_EXISTING},
> {"r+b", GENERIC_WRITE|GENERIC_READ, OPEN_EXISTING},
> {"w+", GENERIC_WRITE|GENERIC_READ, CREATE_ALWAYS},
> {"wb+", GENERIC_WRITE|GENERIC_READ, CREATE_ALWAYS},
> {"w+b", GENERIC_WRITE|GENERIC_READ, CREATE_ALWAYS},
> - {"a+", GENERIC_WRITE|GENERIC_READ, OPEN_ALWAYS },
> - {"ab+", GENERIC_WRITE|GENERIC_READ, OPEN_ALWAYS },
> - {"a+b", GENERIC_WRITE|GENERIC_READ, OPEN_ALWAYS }
> + {"a+", FILE_APPEND_DATA, OPEN_ALWAYS },
> + {"ab+", FILE_APPEND_DATA, OPEN_ALWAYS },
> + {"a+b", FILE_APPEND_DATA, OPEN_ALWAYS }
Cc'ing qemu-sta...@nongnu.org
Thanks for catching this, accidentally truncating files is
certainly not good...
I hit an issue testing this though, this does fix the append
case, but a+, ab+, a+b all imply append+read, while
FILE_APPEND_DATA only grants append access.
FILE_APPEND_DATA|GENERIC_READ seems to work, but I'm not
finding much official documentation on what's valid with
FILE_APPEND_DATA. Do you have a reference that might
confirm this is valid usage? The only reference to
FILE_APPEND_DATA I saw was a single comment in:
https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858(v=vs.85).aspx
I'd like to get this in soon for 2.5 (hard freeze / rc0 is thursday).
> };
>
> static OpenFlags *find_open_flag(const char *mode_str)
> --
> 1.8.5.6
>
