Re: [Libguestfs] [PATCH 4/5] fuse: Fix read for empty files.

Subject: [PATCH 4/5] fuse: Fix read for empty files. Error handling for the guestfs_pread call was incorrect, which meant that empty files could produce spurious error messages. --- fuse/guestmount.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/fuse/guestmount.c b/fuse/guestmount.c index 9d16cef..669bf80 100644 --- a/fuse/guestmount.c +++ b/fuse/guestmount.c @@ -621,8 +621,14 @@ fg_read (const char *path, char *buf, size_t size, off_t offset, if (size > limit) size = limit; + /* Note the correct error handling here is tricky, because in the + * case where the call returns a zero-length buffer, it might return + * NULL. However it won't adjust rsize along the error path, so we + * can set rsize to something beforehand and use that as a flag. + */ + rsize = 1; r = guestfs_pread (g, path, size, offset, &rsize); - if (r == NULL) + if (rsize == 1 && r == NULL) return error ();