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.
changeset: 0:0acdaf898367
tag: tip
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: test
changeset: 1:c5c60883086f
tag: tip
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: Added tag bleah for changeset 0acdaf8983679e0aac16e811534eb49d7ee1f2b4
changeset: 0:0acdaf898367
tag: bleah
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: test
abort: working copy of .hgtags is changed (please commit .hgtags manually)
failed
use of 'hg tag NAME [REV]' is deprecated, please use 'hg tag [-r REV] NAME' instead
abort: use only one form to specify the revision
failed
use of 'hg tag NAME [REV]' is deprecated, please use 'hg tag [-r REV] NAME' instead
0acdaf8983679e0aac16e811534eb49d7ee1f2b4 bleah
0acdaf8983679e0aac16e811534eb49d7ee1f2b4 bleah0
c5c60883086f5526bd3e36814b94a73a4e75e172 bleah1
abort: '\n' cannot be used in a tag name
abort: ':' cannot be used in a tag name