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.
$ hg init
$ cat << EOF > a
> Small Mathematical Series.
> One
> Two
> Three
> Four
> Five
> Hop we are done.
> EOF
$ hg add a
$ hg commit -m ancestor
$ cat << EOF > a
> Small Mathematical Series.
> 1
> 2
> 3
> 4
> 5
> Hop we are done.
> EOF
$ hg commit -m branch1
$ hg co 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat << EOF > a
> Small Mathematical Series.
> 1
> 2
> 3
> 6
> 8
> Hop we are done.
> EOF
$ hg commit -m branch2
created new head
$ hg merge 1
merging a
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg id
618808747361+c0c68e4fe667+ tip
$ cat a
Small Mathematical Series.
<<<<<<< local: 618808747361 - test: branch2
1
2
3
6
8
=======
1
2
3
4
5
>>>>>>> other: c0c68e4fe667 - test: branch1
Hop we are done.
$ hg status
M a
? a.orig
Verify custom conflict markers
$ hg up -q --clean .
$ printf "\n[ui]\nmergemarkertemplate={author} {rev}\n" >> .hg/hgrc
$ hg merge 1
merging a
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ cat a
Small Mathematical Series.
<<<<<<< local: test 2
1
2
3
6
8
=======
1
2
3
4
5
>>>>>>> other: test 1
Hop we are done.
Verify line splitting of custom conflict marker which causes multiple lines
$ hg up -q --clean .
$ cat >> .hg/hgrc <<EOF
> [ui]
> mergemarkertemplate={author} {rev}\nfoo\nbar\nbaz
> EOF
$ hg -q merge 1
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
[1]
$ cat a
Small Mathematical Series.
<<<<<<< local: test 2
1
2
3
6
8
=======
1
2
3
4
5
>>>>>>> other: test 1
Hop we are done.
Verify line trimming of custom conflict marker using multi-byte characters
$ hg up -q --clean .
$ python <<EOF
> fp = open('logfile', 'w')
> fp.write('12345678901234567890123456789012345678901234567890' +
> '1234567890') # there are 5 more columns for 80 columns
>
> # 2 x 4 = 8 columns, but 3 x 4 = 12 bytes
> fp.write(u'\u3042\u3044\u3046\u3048'.encode('utf-8'))
>
> fp.close()
> EOF
$ hg add logfile
$ hg --encoding utf-8 commit --logfile logfile
$ cat >> .hg/hgrc <<EOF
> [ui]
> mergemarkertemplate={desc|firstline}
> EOF
$ hg -q --encoding utf-8 merge 1
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
[1]
$ cat a
Small Mathematical Series.
<<<<<<< local: 123456789012345678901234567890123456789012345678901234567890\xe3\x81\x82... (esc)
1
2
3
6
8
=======
1
2
3
4
5
>>>>>>> other: branch1
Hop we are done.
Verify basic conflict markers
$ hg up -q --clean 2
$ printf "\n[ui]\nmergemarkers=basic\n" >> .hg/hgrc
$ hg merge 1
merging a
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ cat a
Small Mathematical Series.
<<<<<<< local
1
2
3
6
8
=======
1
2
3
4
5
>>>>>>> other
Hop we are done.
internal:merge3
$ hg up -q --clean .
$ hg merge 1 --tool internal:merge3
merging a
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ cat a
Small Mathematical Series.
<<<<<<< local
1
2
3
6
8
||||||| base
One
Two
Three
Four
Five
=======
1
2
3
4
5
>>>>>>> other
Hop we are done.
Add some unconflicting changes on each head, to make sure we really
are merging, unlike :local and :other
$ hg up -C
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 other heads for branch "default"
$ printf "\n\nEnd of file\n" >> a
$ hg ci -m "Add some stuff at the end"
$ hg up -r 1
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ printf "Start of file\n\n\n" > tmp
$ cat a >> tmp
$ mv tmp a
$ hg ci -m "Add some stuff at the beginning"
Now test :merge-other and :merge-local
$ hg merge
merging a
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg resolve --tool :merge-other a
merging a
(no more unresolved files)
$ cat a
Start of file
Small Mathematical Series.
1
2
3
6
8
Hop we are done.
End of file
$ hg up -C
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
1 other heads for branch "default"
$ hg merge --tool :merge-local
merging a
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ cat a
Start of file
Small Mathematical Series.
1
2
3
4
5
Hop we are done.
End of file