ssh: add capability detection at startup
Because older servers don't return any output for unknown commands,
it's tricky to add new commands. The approach is this: we add a
"hello" command that reports any interesting capabilities (and other
things that might be of interest in the future). To detect whether
this new command is supported, we issue both it and our startup
detection command ("between") at the beginning of a connection.
#!/bin/sh
hg init
echo foo > a
echo foo > b
hg add a b
hg ci -m "test" -d "1000000 0"
echo blah > a
hg ci -m "branch a" -d "1000000 0"
hg co 0
echo blah > b
hg ci -m "branch b" -d "1000000 0"
HGMERGE=true hg merge 1
hg ci -m "merge b/a -> blah" -d "1000000 0"
hg co 1
HGMERGE=true hg merge 2
hg ci -m "merge a/b -> blah" -d "1000000 0"
hg log
hg debugindex .hg/00changelog.i
echo
echo 1
hg manifest 1
echo 2
hg manifest 2
echo 3
hg manifest 3
echo 4
hg manifest 4
echo
hg debugindex .hg/data/a.i
hg verify