diff options
| -rw-r--r-- | qemu-char.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/qemu-char.c b/qemu-char.c index a50b8fb3a3..27f2dbbbb5 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -4234,14 +4234,26 @@ static CharDriverState *qmp_chardev_open_file(const char *id, ChardevFile *file = backend->u.file.data; ChardevCommon *common = qapi_ChardevFile_base(file); HANDLE out; + DWORD accessmode; + DWORD flags; if (file->has_in) { error_setg(errp, "input file not supported"); return NULL; } - out = CreateFile(file->out, GENERIC_WRITE, FILE_SHARE_READ, NULL, - OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); + if (file->has_append && file->append) { + /* Append to file if it already exists. */ + accessmode = FILE_GENERIC_WRITE & ~FILE_WRITE_DATA; + flags = OPEN_ALWAYS; + } else { + /* Truncate file if it already exists. */ + accessmode = GENERIC_WRITE; + flags = CREATE_ALWAYS; + } + + out = CreateFile(file->out, accessmode, FILE_SHARE_READ, NULL, flags, + FILE_ATTRIBUTE_NORMAL, NULL); if (out == INVALID_HANDLE_VALUE) { error_setg(errp, "open %s failed", file->out); return NULL; |