Protocol switch from using generators to stream-like objects. This allows the the pull side to precisely control how much data is read so that another encapsulation layer is not needed. An http client gets a response with a finite size. Because ssh clients need to keep the stream open, we must not read more data than is sent in a response. But due to the streaming nature of the changegroup scheme, only the piece that's parsing the data knows how far it's allowed to read. This means the generator scheme isn't fine-grained enough. Instead we need file-like objects with a read(x) method. This switches everything for push/pull over to using file-like objects rather than generators.

#!/bin/bash

set -x

# No local source
hg clone a b
echo $?

# No remote source
hg clone http://127.0.0.1:3121/a b
echo $?
rm -rf b # work around bug with http clone

# Inaccessible source
mkdir a
chmod 000 a
hg clone a b
echo $?

# Inaccessible destination
mkdir b
cd b
hg init
hg clone . ../a
echo $?
cd ..
chmod 700 a
rm -rf a b

# Source of wrong type
mkfifo a
hg clone a b
echo $?
rm a

# Default destination, same directory
mkdir q
cd q
hg init
cd ..
hg clone q

true