Re: BufFileSize() doesn't work on a "shared" BufFiles

On Mon, Apr 30, 2018 at 10:18 AM, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> Perhaps that would be OK, if it was properly commented. But it's not
> actually hard to make BufFileSize() work on shared files, too, so I think we
> should do that.

I agree that this could use a comment, but I don't see much point in
adding the extra FileSeek(). The fact that fd.c is unwilling to track
filesize for non-temp files (where "non-temp" means a
PathNameOpenTemporaryFile()-returned/exported file) is due to
vfdP->fileSize being involved in temp_file_limit enforcement. Maybe a
FD_TEMP_FILE_LIMIT assertion within FileGetSize() would help?

> Another little bug I noticed is that BufFileAppend() incorrectly resets the
> 'offsets' of the source files. You won't notice if you call BufFileAppend()
> immediately after BufFileOpenShared(), but if you had called BufFileSeek()
> or BufFileRead() on the shared BufFile handle before calling
> BufFileAppend(), it would get confused.

Seems worth fixing.

-- 
Peter Geoghegan