exchange: use v2 bundles for modern compression engines (issue5506)
Previously, `hg bundle zstd` on a non-generaldelta repo would
attempt to use a v1 bundle. This would fail because zstd is not
supported on v1 bundles.
This patch changes the behavior to automatically use a v2 bundle
when the user explicitly requests a bundlespec that is a compression
engine not supported on v1. If the bundlespec is <engine>-v1, it is
still explicitly rejected because that request cannot be fulfilled.
#!/usr/bin/env bash
hg init remote
cd remote
echo "0" >> afile
hg add afile
hg commit -m "0.0"
echo "1" >> afile
hg commit -m "0.1"
echo "2" >> afile
hg commit -m "0.2"
echo "3" >> afile
hg commit -m "0.3"
hg update -C 0
echo "1" >> afile
hg commit -m "1.1"
echo "2" >> afile
hg commit -m "1.2"
echo "a line" > fred
echo "3" >> afile
hg add fred
hg commit -m "1.3"
hg mv afile adifferentfile
hg commit -m "1.3m"
hg update -C 3
hg mv afile anotherfile
hg commit -m "0.3m"
hg bundle -a ../remote.hg
cd ..
rm -Rf remote