On 26/07/2016 19:11, Stefan Weil wrote:
> On Windows, such files were not truncated like on all other hosts.
> Now we also test whether truncation is needed when running on Windows.
>
> Reported-by: Benjamin David Lunt <f...@fysnet.net>
> Signed-off-by: Stefan Weil <s...@weilnetz.de>
> ---
> qemu-char.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/qemu-char.c b/qemu-char.c
> index e4b8448..7de63c8 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -4197,14 +4197,23 @@ static CharDriverState *qmp_chardev_open_file(const
> char *id,
> ChardevFile *file = backend->u.file.data;
> ChardevCommon *common = qapi_ChardevFile_base(file);
> HANDLE out;
> + DWORD flags;
>
> if (file->has_in) {
> error_setg(errp, "input file not supported");
> return NULL;
> }
>
> + if (file->has_append && file->append) {
> + /* Append to file if it already exists. */
> + flags = OPEN_ALWAYS;
> + } else {
> + /* Truncate file if it already exists. */
> + flags = CREATE_ALWAYS;
> + }
> +
> out = CreateFile(file->out, GENERIC_WRITE, FILE_SHARE_READ, NULL,
GENERIC_WRITE does not include FILE_APPEND_DATA. You should also change
the access rights to FILE_GENERIC_WRITE & ~FILE_WRITE_DATA in the append
case; see commit 52074d0f662fc51293d4cde8077631f754784405 for a similar
case in qemu-ga.
Thanks,
Paolo
> - OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
> + flags, FILE_ATTRIBUTE_NORMAL, NULL);
> if (out == INVALID_HANDLE_VALUE) {
> error_setg(errp, "open %s failed", file->out);
> return NULL;
>
