update: warn about other topological heads on bare update
A concern around the user experience of Mercurial is user getting stuck on there
own topological branch forever. For example, someone pulling another topological
branch, missing that message in pull asking them to merge and getting stuck on
there own local branch.
The current way to "address" this concern was for bare 'hg update' to target the
tipmost (also latest pulled) changesets and complain when the update was not
linear. That way, failure to merge newly pulled changesets would result in some
kind of failure.
Yet the failure was quite obscure, not working in all cases (eg: commit right
after pull) and the behavior was very impractical in the common case
(eg:
issue4673).
To be able to change that behavior, we need to provide other ways to alert a
user stucks on one of many topological head. We do so with an extra message after
bare update:
1 other heads for branch "default"
Bookmark get its own special version:
1 other divergent bookmarks for "foobar"
There is significant room to improve the message itself, and we should augment
it with hint about how to see theses other heads or handle the situation (see
in-line comment). But having "a" message is already a significant improvement
compared to the existing situation. Once we have it we can iterate on a better
version of it. As having such message is an important step toward changing the
default destination for update and other nicety, I would like to move forward
quickly on getting such message.
This was discussed during London - October 2015 Sprint.
setup
$ cat >> $HGRCPATH <<EOF
> [extensions]
> blackbox=
> mock=$TESTDIR/mockblackbox.py
> mq=
> EOF
$ hg init blackboxtest
$ cd blackboxtest
command, exit codes, and duration
$ echo a > a
$ hg add a
$ hg blackbox
1970/01/01 00:00:00 bob (*)> add a (glob)
1970/01/01 00:00:00 bob (*)> add a exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob (*)> blackbox (glob)
incoming change tracking
create two heads to verify that we only see one change in the log later
$ hg commit -ma
$ hg up null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo b > b
$ hg commit -Amb
adding b
created new head
clone, commit, pull
$ hg clone . ../blackboxtest2
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo c > c
$ hg commit -Amc
adding c
$ cd ../blackboxtest2
$ hg pull
pulling from $TESTTMP/blackboxtest (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
$ hg blackbox -l 6
1970/01/01 00:00:00 bob (*)> pull (glob)
1970/01/01 00:00:00 bob (*)> updated served branch cache in * seconds (glob)
1970/01/01 00:00:00 bob (*)> wrote served branch cache with 1 labels and 2 nodes (glob)
1970/01/01 00:00:00 bob (*)> 1 incoming changes - new heads: d02f48003e62 (glob)
1970/01/01 00:00:00 bob (*)> pull exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob (*)> blackbox -l 6 (glob)
we must not cause a failure if we cannot write to the log
$ hg rollback
repository tip rolled back to revision 1 (undo pull)
$ mv .hg/blackbox.log .hg/blackbox.log-
$ mkdir .hg/blackbox.log
$ hg --debug incoming
warning: cannot write to blackbox.log: * (glob)
comparing with $TESTTMP/blackboxtest (glob)
query 1; heads
searching for changes
all local heads known remotely
changeset: 2:d02f48003e62c24e2659d97d30f2a83abe5d5d51
tag: tip
phase: draft
parent: 1:6563da9dcf87b1949716e38ff3e3dfaa3198eb06
parent: -1:0000000000000000000000000000000000000000
manifest: 2:ab9d46b053ebf45b7996f2922b9893ff4b63d892
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files+: c
extra: branch=default
description:
c
$ hg pull
pulling from $TESTTMP/blackboxtest (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
a failure reading from the log is fatal
$ hg blackbox -l 3
abort: *$TESTTMP/blackboxtest2/.hg/blackbox.log* (glob)
[255]
$ rmdir .hg/blackbox.log
$ mv .hg/blackbox.log- .hg/blackbox.log
backup bundles get logged
$ touch d
$ hg commit -Amd
adding d
created new head
$ hg strip tip
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/*-backup.hg (glob)
$ hg blackbox -l 6
1970/01/01 00:00:00 bob (*)> strip tip (glob)
1970/01/01 00:00:00 bob (*)> saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/73f6ee326b27-7612e004-backup.hg (glob)
1970/01/01 00:00:00 bob (*)> updated base branch cache in * seconds (glob)
1970/01/01 00:00:00 bob (*)> wrote base branch cache with 1 labels and 2 nodes (glob)
1970/01/01 00:00:00 bob (*)> strip tip exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob (*)> blackbox -l 6 (glob)
extension and python hooks - use the eol extension for a pythonhook
$ echo '[extensions]' >> .hg/hgrc
$ echo 'eol=' >> .hg/hgrc
$ echo '[hooks]' >> .hg/hgrc
$ echo 'update = echo hooked' >> .hg/hgrc
$ hg update
hooked
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 other heads for branch "default"
$ hg blackbox -l 6
1970/01/01 00:00:00 bob (*)> update (glob)
1970/01/01 00:00:00 bob (*)> writing .hg/cache/tags2-visible with 0 tags (glob)
1970/01/01 00:00:00 bob (*)> pythonhook-preupdate: hgext.eol.preupdate finished in * seconds (glob)
1970/01/01 00:00:00 bob (*)> exthook-update: echo hooked finished in * seconds (glob)
1970/01/01 00:00:00 bob (*)> update exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob (*)> blackbox -l 6 (glob)
log rotation
$ echo '[blackbox]' >> .hg/hgrc
$ echo 'maxsize = 20 b' >> .hg/hgrc
$ echo 'maxfiles = 3' >> .hg/hgrc
$ hg status
$ hg status
$ hg status
$ hg tip -q
2:d02f48003e62
$ ls .hg/blackbox.log*
.hg/blackbox.log
.hg/blackbox.log.1
.hg/blackbox.log.2
$ cd ..
$ hg init blackboxtest3
$ cd blackboxtest3
$ hg blackbox
1970/01/01 00:00:00 bob (*)> blackbox (glob)
$ mv .hg/blackbox.log .hg/blackbox.log-
$ mkdir .hg/blackbox.log
$ sed -e 's/\(.*test1.*\)/#\1/; s#\(.*commit2.*\)#os.rmdir(".hg/blackbox.log")\nos.rename(".hg/blackbox.log-", ".hg/blackbox.log")\n\1#' $TESTDIR/test-dispatch.py > ../test-dispatch.py
$ python ../test-dispatch.py
running: add foo
result: 0
running: commit -m commit1 -d 2000-01-01 foo
result: None
running: commit -m commit2 -d 2000-01-02 foo
result: None
running: log -r 0
changeset: 0:0e4634943879
user: test
date: Sat Jan 01 00:00:00 2000 +0000
summary: commit1
result: None
running: log -r tip
changeset: 1:45589e459b2e
tag: tip
user: test
date: Sun Jan 02 00:00:00 2000 +0000
summary: commit2
result: None
$ hg blackbox
1970/01/01 00:00:00 bob (*)> blackbox (glob)
1970/01/01 00:00:00 bob (*)> blackbox exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob (*)> blackbox (glob)
cleanup
$ cd ..