[v2] qga: fix append file open modes for win32

For append file open modes, use FILE_APPEND_DATA for the desired access
for writing at the end of the file.

Version 2:
For "a+", "ab+", and "a+b" modes use FILE_APPEND_DATA|GENERIC_READ.
ORing in GENERIC_READ starts a read at the begining of the file.  All
writes will append to the end fo the file.

Added white space to maintain the alignment of the guest_file_open_modes[].

Signed-off-by: Kirk Allan <kallan@suse.com>
---
 qga/commands-win32.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

Quoting Kirk Allan (2015-11-10 17:19:11)
> For append file open modes, use FILE_APPEND_DATA for the desired access
> for writing at the end of the file.
> 
> Version 2:
> For "a+", "ab+", and "a+b" modes use FILE_APPEND_DATA|GENERIC_READ.
> ORing in GENERIC_READ starts a read at the begining of the file.  All
> writes will append to the end fo the file.
> 
> Added white space to maintain the alignment of the guest_file_open_modes[].
> 
> Signed-off-by: Kirk Allan <kallan@suse.com>

Thanks, applied to qga tree with changes discussed in v1 thread:

  https://github.com/mdroth/qemu/commits/qga

> ---
>  qga/commands-win32.c | 28 ++++++++++++++--------------
>  1 file changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index a5306e7..5a75c3d 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -66,20 +66,20 @@ typedef struct OpenFlags {
>      DWORD creation_disposition;
>  } OpenFlags;
>  static OpenFlags guest_file_open_modes[] = {
> -    {"r",   GENERIC_READ,               OPEN_EXISTING},
> -    {"rb",  GENERIC_READ,               OPEN_EXISTING},
> -    {"w",   GENERIC_WRITE,              CREATE_ALWAYS},
> -    {"wb",  GENERIC_WRITE,              CREATE_ALWAYS},
> -    {"a",   GENERIC_WRITE,              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  }
> +    {"r",   GENERIC_READ,                  OPEN_EXISTING},
> +    {"rb",  GENERIC_READ,                  OPEN_EXISTING},
> +    {"w",   GENERIC_WRITE,                 CREATE_ALWAYS},
> +    {"wb",  GENERIC_WRITE,                 CREATE_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+",  FILE_APPEND_DATA|GENERIC_READ, OPEN_ALWAYS  },
> +    {"ab+", FILE_APPEND_DATA|GENERIC_READ, OPEN_ALWAYS  },
> +    {"a+b", FILE_APPEND_DATA|GENERIC_READ, OPEN_ALWAYS  }
>  };
> 
>  static OpenFlags *find_open_flag(const char *mode_str)
> -- 
> 1.8.5.6
>