On Mon, Feb 7, 2011 at 4:26 PM, Blair Zajac <bl...@orcaware.com> wrote:
> [I sent this to d...@apr.apache.org but haven't received a response. Thread
> here:
> http://mail-archives.apache.org/mod_mbox/apr-dev/201102.mbox/%3cf7b1928d-d32f-48dd-b8d9-80b26906a...@orcaware.com%3E
> . Given the importance of writing complete files for svn, could somebody
> take a look and see if this is a valid issue].
>
> I was looking at apr_file_flush() and think I found a bug where if write()
> doesn't do a full write, then the apr_file_t will destroy and buffered data
> because it sets its internal buffer position back to 0.
Yeah, that looks like a bug.
> Here's a patch for this:
>
> Index: file_io/unix/readwrite.c
> ===================================================================
> --- file_io/unix/readwrite.c (revision 1067340)
> +++ file_io/unix/readwrite.c (working copy)
> @@ -409,7 +409,11 @@
> rv = errno;
> } else {
> thefile->filePtr += written;
> - thefile->bufpos = 0;
> + if (written != thefile->bufpos)
> + memmove(thefile->buffer,
> + thefile->buffer + written,
> + thefile->bufpos - written);
> + thefile->bufpos -= written;
> }
> }
>
> Beyond this, there's no a mechanism to report that all the buffered data
> didn't get into the file. Perhaps apr_file_flush() should loop until the
> entire buffer is written or it gets a non-EINTR error?
I think it you're right, it should loop around. Good catch!
-John
