On Tue, Oct 08, 2019 at 03:22:57PM -0400, Joey Hess wrote:
> I'm surprised to find that git cat-file --batch, on a Linux system,
> strips the \r from an input like "HEAD:foo\r\n"
>
> It's obvious, of course, that it will remove the newline, and so this
> interface cannot be used to query about a filename that, for some
> horrible reason[1], contains a newline. But very surprising that it
> cannot be used for filename that contains a carriage return, at least
> on a non-Windows system.
This is likely due to b42ca3dd0f (cat-file: read batch stream with
strbuf_getline(), 2015-10-28), and the matching c8aa9fdf5d (strbuf: make
strbuf_getline_crlf() global, 2015-10-28).
I agree it's a bit surprising (though OTOH, I imagine the old behavior
surprised some people in the opposite direction).
> The docs for cat-file --batch say the list of objects is separated by
> linefeeds. I don't know if updating the docs is the best fix.
> (I'd be happy to use a -z if it had one.)
Yeah, I agree that a -z option is the best path forward. For non-z
input, I'm tempted to say we could unquote entries that start with a
double-quote (the match to how we handle filenames in non-z diff
output). That would mean breaking compatibility for refnames that start
with a quote, though. If we just add a new "-z", that's less disruptive
_and_ easier to use.
I suspect it's not entirely sufficient for clean input, though. You're
not feeding filenames but rather full "object names". I wouldn't be
surprised if we mis-parse "$rev:$path" when $path has "@{}" or similar
in it.
So what you may actually want is some more robust input format that lets
you specify the filename as an independent NUL-terminated entity.
-Peff
