templatekw: choose {latesttag} by len(changes), not date (
issue5659)
As Augie reported in the bug, the current heuristic of choosing the
best tag of a merge commit by taking the one with newest tag (in terms
of tagging date) currently fails in the Mercurial repo itself. Copying
the example from Yuya:
$ hg glog -T '{node|short} {latesttag}+{latesttagdistance}\n' \
-r '4.2.3: & (merge() + parents(merge()) + tag())'
o
02a745c20121 4.2.3+5
|\
| o
86aca74a063b 4.2.3+4
| |\
| | o
e6d8ee3c9ec3 4.3-rc+109
| | |
| | ~
o |
a3ce07e2dde5 4.3.1+2
: |
o |
3fee7f7d2da0 4.3.1+0
|/
o
98e990bb7330 4.2.3+3
|\
| ~
o
506d7e48fbe6 4.2.3+2
:
o
943c91326b23 4.2.3+0
|
~
It seems to me like the best choice is the tag with the smallest
number of changes since it (across all paths, not the longest single
path). So that's what this patch does, even though it's
costly. Best-of-5 timings for Yuya's command above shows a slowdown
from 1.293s to 1.610s. We can optimize it later.
Differential Revision: https://phab.mercurial-scm.org/D447
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ hg init r
$ cd r
$ for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
$ hg book -r 1 will-move-backwards
$ hg book -r 2 two
$ hg book -r 2 also-two
$ hg book -r 3 three
$ hg book -r 4 four
$ hg book -r tip five
$ hg log --graph
@ changeset: 5:652413bf663e
| bookmark: five
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| bookmark: four
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| bookmark: three
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| bookmark: also-two
| bookmark: two
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| bookmark: will-move-backwards
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ HGEDITOR=cat hg histedit 1
pick d2ae7f538514 1 b
pick 177f92b77385 2 c
pick 055a42cdd887 3 d
pick e860deea161a 4 e
pick 652413bf663e 5 f
# Edit history between d2ae7f538514 and 652413bf663e
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ hg histedit 1 --commands - --verbose << EOF | grep histedit
> pick 177f92b77385 2 c
> drop d2ae7f538514 1 b
> pick 055a42cdd887 3 d
> fold e860deea161a 4 e
> pick 652413bf663e 5 f
> EOF
saved backup bundle to $TESTTMP/r/.hg/strip-backup/96e494a2d553-45c027ab-histedit.hg (glob)
$ hg log --graph
@ changeset: 3:cacdfd884a93
| bookmark: five
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:59d9f330561f
| bookmark: four
| bookmark: three
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 1:b346ab9a313d
| bookmark: also-two
| bookmark: two
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 0:cb9a9f314b8b
bookmark: will-move-backwards
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ HGEDITOR=cat hg histedit 1
pick b346ab9a313d 1 c
pick 59d9f330561f 2 d
pick cacdfd884a93 3 f
# Edit history between b346ab9a313d and cacdfd884a93
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ hg histedit 1 --commands - --verbose << EOF | grep histedit
> pick b346ab9a313d 1 c
> pick cacdfd884a93 3 f
> pick 59d9f330561f 2 d
> EOF
saved backup bundle to $TESTTMP/r/.hg/strip-backup/59d9f330561f-073008af-histedit.hg (glob)
We expect 'five' to stay at tip, since the tipmost bookmark is most
likely the useful signal.
$ hg log --graph
@ changeset: 3:c04e50810e4b
| bookmark: five
| bookmark: four
| bookmark: three
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:c13eb81022ca
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 1:b346ab9a313d
| bookmark: also-two
| bookmark: two
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 0:cb9a9f314b8b
bookmark: will-move-backwards
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a