view tests/test-pager-legacy.t @ 42619:20d0e59be79b

tests: show the files fields of changelogs for many merges

I don't think there's coverage for many of the subtle cases, and I
found it hard to understand what the code is doing by reading it.  The
test takes 40s to run on a laptop, or 9s with --chg.

I have yet to find a description of what the files field is supposed
to be for merges. I thought it could be one of:
1. the files added/modified/removed relative to p1 (wouldn't seem
  useful, but `hg diff -c -r mergerev` has this behavior)
2. the files with filelog nodes not in either parent (i.e., what is
needed to create a bundle out of a commit)
3. the files added/removed/modified files by merge itself [1]

It's clearly not 1, because file contents merges are symmetric. It's
clearly not 2 because removed files and exec bit changes are
listed. It's also not 3 but I think it's intended to be 3 and the
differences are bugs.

Assuming 3, the test shows that, for merges, the list of files both
overapproximates and underapproximates. All the cases involve file
changes not in the filelog but in the manifest (existence of file
at revision, exec bit and file vs symlink).

I didn't look at all underapproximations, but they looked minor. The
two overapproximations are problematic though because they both cause
potentially long lists of files when merging cleanly.


[1] even what it means for the merge commit itself to change a file is
not completely trivial. A file in the merge being the same as in one
of the parent is too lax as it would consider that merges change
nothing when they revert all the changes done on one side. The
criteria used in the test and in the next commit for "merge didn't
touch a file" is:
- the parents and the merge all have the same file
- or, one parent didn't touch the file and the other parent contains
  the same file as the merge

Differential Revision: https://phab.mercurial-scm.org/D6612

  $ cat >> fakepager.py <<EOF
  > import sys
  > for line in sys.stdin:
  >     sys.stdout.write('paged! %r\n' % line)
  > EOF

Enable ui.formatted because pager won't fire without it, and set up
pager and tell it to use our fake pager that lets us see when the
pager was running.
  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > formatted = yes
  > color = no
  > [extensions]
  > pager=
  > [pager]
  > pager = "$PYTHON" $TESTTMP/fakepager.py
  > EOF

  $ hg init repo
  $ cd repo
  $ echo a >> a
  $ hg add a
  $ hg ci -m 'add a'
  $ for x in `"$PYTHON" $TESTDIR/seq.py 1 10`; do
  >   echo a $x >> a
  >   hg ci -m "modify a $x"
  > done

By default diff and log are paged, but summary is not:

  $ hg diff -c 2 --pager=yes
  paged! 'diff -r f4be7687d414 -r bce265549556 a\n'
  paged! '--- a/a\tThu Jan 01 00:00:00 1970 +0000\n'
  paged! '+++ b/a\tThu Jan 01 00:00:00 1970 +0000\n'
  paged! '@@ -1,2 +1,3 @@\n'
  paged! ' a\n'
  paged! ' a 1\n'
  paged! '+a 2\n'

  $ hg log --limit 2
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

  $ hg summary
  parent: 10:46106edeeb38 tip
   modify a 10
  branch: default
  commit: (clean)
  update: (current)
  phases: 11 draft

We can enable the pager on summary:

  $ hg --config pager.attend-summary=yes summary
  paged! 'parent: 10:46106edeeb38 tip\n'
  paged! ' modify a 10\n'
  paged! 'branch: default\n'
  paged! 'commit: (clean)\n'
  paged! 'update: (current)\n'
  paged! 'phases: 11 draft\n'

  $ hg --config pager.attend-diff=no diff -c 2
  diff -r f4be7687d414 -r bce265549556 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@
   a
   a 1
  +a 2

If we completely change the attend list that's respected:
  $ hg --config pager.attend=summary diff -c 2
  diff -r f4be7687d414 -r bce265549556 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@
   a
   a 1
  +a 2

If 'log' is in attend, then 'history' should also be paged:
  $ hg history --limit 2 --config pager.attend=log
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

Possible bug: history is explicitly ignored in pager config, but
because log is in the attend list it still gets pager treatment.

  $ hg history --limit 2 --config pager.attend=log \
  >   --config pager.ignore=history
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

Possible bug: history is explicitly marked as attend-history=no, but
it doesn't fail to get paged because log is still in the attend list.

  $ hg history --limit 2 --config pager.attend-history=no
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

Possible bug: disabling pager for log but enabling it for history
doesn't result in history being paged.

  $ hg history --limit 2 --config pager.attend-log=no \
  > --config pager.attend-history=yes
  changeset:   10:46106edeeb38
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 10
  
  changeset:   9:6dd8ea7dd621
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 9
  
Pager should not start if stdout is not a tty.

  $ hg log -l1 -q --config ui.formatted=False
  10:46106edeeb38

Pager with color enabled allows colors to come through by default,
even though stdout is no longer a tty.
  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > color = always
  > [color]
  > mode = ansi
  > EOF
  $ hg log --limit 3
  paged! '\x1b[0;33mchangeset:   10:46106edeeb38\x1b[0m\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! '\x1b[0;33mchangeset:   9:6dd8ea7dd621\x1b[0m\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'
  paged! '\x1b[0;33mchangeset:   8:cff05a6312fe\x1b[0m\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 8\n'
  paged! '\n'

Pager works with shell aliases.

  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > echoa = !echo a
  > EOF

  $ hg echoa
  a
  $ hg --config pager.attend-echoa=yes echoa
  paged! 'a\n'

Pager attributes should be copied to mq repo. Otherwise pager would be started
twice and color mode would be lost.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > mq =
  > EOF
  $ hg init --mq
  $ hg qnew foo.patch
  $ hg qpop
  popping foo.patch
  patch queue now empty
  $ hg ci --mq -m 'commit patches'
  $ hg log --mq --debug
  starting pager for command 'extension-via-attend-log'
  paged! '\x1b[0;33mchangeset:   0:6cc2ded15503e368aaf76b6cc3d12f320c9e3b87\x1b[0m\n'
  paged! 'tag:         tip\n'
  paged! 'phase:       draft\n'
  paged! 'parent:      -1:0000000000000000000000000000000000000000\n'
  paged! 'parent:      -1:0000000000000000000000000000000000000000\n'
  paged! 'manifest:    0:4980de1ae1b612014d5bcfa9507da84ce8891daa\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'files+:      .hgignore foo.patch series\n'
  paged! 'extra:       branch=default\n'
  paged! 'description:\n'
  paged! 'commit patches\n'
  paged! '\n'
  paged! '\n'

Pager works with hg aliases including environment variables.

  $ cat >> $HGRCPATH <<'EOF'
  > [alias]
  > printa = log -T "$A\n" -r 0
  > EOF

  $ A=1 hg --config pager.attend-printa=yes printa
  paged! '1\n'
  $ A=2 hg --config pager.attend-printa=yes printa
  paged! '2\n'

Something that's explicitly attended is still not paginated if the
pager is globally set to off using a flag:
  $ A=2 hg --config pager.attend-printa=yes printa --pager=no
  2

Pager should not override the exit code of other commands

  $ cat >> $TESTTMP/fortytwo.py <<'EOF'
  > from mercurial import commands, registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'fortytwo', [], b'fortytwo', norepo=True)
  > def fortytwo(ui, *opts):
  >     ui.write(b'42\n')
  >     return 42
  > EOF

  $ cat >> $HGRCPATH <<'EOF'
  > [extensions]
  > fortytwo = $TESTTMP/fortytwo.py
  > EOF

  $ hg fortytwo --pager=on
  paged! '42\n'
  [42]