tests/test-single-head.t

wix: tell ComponentSearch that it is finding a directory (not a file)

This is to fix an issue we've noticed where fresh installations start at
`C:\Program Files\Mercurial`, and then upgrades "walk up" the tree and end up in
`C:\Program Files` and finally `C:\` (where they stay).

ComponentSearch defaults to finding files, which I think means "it produces a
string like `C:\Program Files\Mercurial`", whereas with the type being
explicitly a directory, it would return `C:\Program Files\Mercurial\` (note the
final trailing backslash). Presumably, a latter step then tries to turn that
file name into a proper directory, by removing everything after the last `\`.

This could likely also be fixed by actually searching for the component for
hg.exe itself. That seemed a lot more complicated, as the GUID for hg.exe isn't
known in this file (it's one of the "auto-derived" ones). We could also consider
adding a Condition that I think could check the Property and ensure it's either
empty or ends in a trailing slash, but that would be an installer runtime check
and I'm not convinced it'd actually be useful.

This will *not* cause existing installations that are in one of the bad
directories to fix themselves. Doing that would require a fair amount more
understanding of wix and windows installer than I have, and it *probably*
wouldn't be possible to be 100% correct about it either (there's nothing
preventing a user from intentionally installing it in C:\, though I don't know
why they would do so).

If someone wants to tackle fixing existing installations, I think that the first
installation is actually the only one that shows up in "Add or Remove Programs",
and that its registry keys still exist. You might be able to find something
under HKEY_USERS that lists both the "good" and the "bad" InstallDirs. Mine was
under `HKEY_USERS\S-1-5-18\Software\Mercurial\InstallDir` (C:\), and
`HKEY_USERS\S-1-5-21-..numbers..\Software\Mercurial\InstallDir` (C:\Program
Files\Mercurial). If you find exactly two, with one being the default path, and
the other being a prefix of it, the user almost certainly hit this bug :D

We had originally thought that this bug might be due to unattended
installations/upgrades, but I no longer think that's the case. We were able to
reproduce the issue by uninstalling all copies of Mercurial I could find,
installing one version (it chose the correct location), and then starting the
installer for a different version (higher or lower didn't matter). I did not
need to deal with an unattended or headless installation/upgrade to trigger the
issue, but it's possible that my system was "primed" for this bug to happen
because of a previous unattended installation/upgrade.

Differential Revision: https://phab.mercurial-scm.org/D9891

=====================
Test workflow options
=====================

  $ . "$TESTDIR/testlib/obsmarker-common.sh"

Test single head enforcing - Setup
=============================================

  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > evolution = all
  > EOF
  $ hg init single-head-server
  $ cd single-head-server
  $ cat <<EOF >> .hg/hgrc
  > [phases]
  > publish = no
  > [experimental]
  > single-head-per-branch = yes
  > EOF
  $ mkcommit ROOT
  $ mkcommit c_dA0
  $ cd ..

  $ hg clone single-head-server client
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

Test single head enforcing - with branch only
---------------------------------------------

  $ cd client

continuing the current defaultbranch

  $ mkcommit c_dB0
  $ hg push
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files

creating a new branch

  $ hg up 'desc("ROOT")'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg branch branch_A
  marked working directory as branch branch_A
  (branches are permanent and global, did you want a bookmark?)
  $ mkcommit c_aC0
  $ hg push --new-branch
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)

Create a new head on the default branch

  $ hg up 'desc("c_dA0")'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkcommit c_dD0
  created new head
  $ hg push -f
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  transaction abort!
  rollback completed
  abort: rejecting multiple heads on branch "default"
  (2 heads: 286d02a6e2a2 9bf953aa81f6)
  [255]

remerge them

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ mkcommit c_dE0
  $ hg push
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files

Test single head enforcing - after rewrite
------------------------------------------

  $ mkcommit c_dF0
  $ hg push
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  $ hg commit --amend -m c_dF1
  $ hg push
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 1 files (+1 heads)
  1 new obsolescence markers
  obsoleted 1 changesets

Check it does not interfer with strip
-------------------------------------

setup

  $ hg branch branch_A --force
  marked working directory as branch branch_A
  $ mkcommit c_aG0
  created new head
  $ hg update 'desc("c_dF1")'
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkcommit c_dH0
  $ hg update 'desc("c_aG0")'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ mkcommit c_aI0
  $ hg log -G
  @    changeset:   10:49003e504178
  |\   branch:      branch_A
  | |  tag:         tip
  | |  parent:      8:a33fb808fb4b
  | |  parent:      3:840af1c6bc88
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     c_aI0
  | |
  | | o  changeset:   9:fe47ea669cea
  | | |  parent:      7:99a2dc242c5d
  | | |  user:        test
  | | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | | |  summary:     c_dH0
  | | |
  | o |  changeset:   8:a33fb808fb4b
  | |/   branch:      branch_A
  | |    user:        test
  | |    date:        Thu Jan 01 00:00:00 1970 +0000
  | |    summary:     c_aG0
  | |
  | o  changeset:   7:99a2dc242c5d
  | |  parent:      5:6ed1df20edb1
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     c_dF1
  | |
  | o    changeset:   5:6ed1df20edb1
  | |\   parent:      4:9bf953aa81f6
  | | |  parent:      2:286d02a6e2a2
  | | |  user:        test
  | | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | | |  summary:     c_dE0
  | | |
  | | o  changeset:   4:9bf953aa81f6
  | | |  parent:      1:134bc3852ad2
  | | |  user:        test
  | | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | | |  summary:     c_dD0
  | | |
  o | |  changeset:   3:840af1c6bc88
  | | |  branch:      branch_A
  | | |  parent:      0:ea207398892e
  | | |  user:        test
  | | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | | |  summary:     c_aC0
  | | |
  | o |  changeset:   2:286d02a6e2a2
  | |/   user:        test
  | |    date:        Thu Jan 01 00:00:00 1970 +0000
  | |    summary:     c_dB0
  | |
  | o  changeset:   1:134bc3852ad2
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     c_dA0
  |
  o  changeset:   0:ea207398892e
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     ROOT
  

actual stripping

  $ hg strip --config extensions.strip= --rev 'desc("c_dH0")'
  saved backup bundle to $TESTTMP/client/.hg/strip-backup/fe47ea669cea-a41bf5a9-backup.hg

Test that closing heads are ignored by default
-----------------------------------------------

  $ hg up 'desc("c_aG0")'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mkcommit c_aJ0
  created new head

pushing the new head should fails

  $ hg push -f
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  transaction abort!
  rollback completed
  abort: rejecting multiple heads on branch "branch_A"
  (2 heads: 49003e504178 468bd81ccc5d)
  [255]


closing the head and pushing should succeed

  $ mkcommit c_aK0 --close-branch
  $ hg push -f
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 4 changes to 4 files (-1 heads)


Test that closing heads can be explicitly accounted for
-------------------------------------------------------

  $ cat <<EOF >> $TESTTMP/single-head-server/.hg/hgrc
  > [experimental]
  > single-head-per-branch:account-closed-heads = yes
  > EOF

  $ hg up 'desc("c_aG0")'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mkcommit c_aL0
  created new head
  $ mkcommit c_aM0 --close-branch
  $ hg push -f
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  transaction abort!
  rollback completed
  abort: rejecting multiple heads on branch "branch_A"
  (3 heads: 49003e504178 5254bcccab93 42b9fe70a3c1)
  [255]


Test that config can be overriden as the boolean it is
------------------------------------------------------

  $ cat <<EOF >> $TESTTMP/single-head-server/.hg/hgrc
  > [experimental]
  > single-head-per-branch = no
  > EOF

Because of previous test, we'll also push c_aL0 and c_aM0.

  $ hg out -T "{desc}\n"
  comparing with $TESTTMP/single-head-server
  searching for changes
  c_aL0
  c_aM0

Let's make a new head and push everything. The server feedback will mention
exactly one new head because c_aM0 is closed.

  $ hg up 'desc("c_aG0")'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mkcommit c_aN0
  created new head
  $ hg push -f
  pushing to $TESTTMP/single-head-server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files (+1 heads)
  $ cd ..


Test that singe-head-per-branch can be restricted to public changes
-------------------------------------------------------------------

  $ hg clone -r 49003e504178 single-head-server public-only
  adding changesets
  adding manifests
  adding file changes
  added 9 changesets with 9 changes to 9 files
  1 new obsolescence markers
  new changesets ea207398892e:49003e504178 (9 drafts)
  updating to branch branch_A
  9 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd public-only
  $ cat <<EOF >> .hg/hgrc
  > [phases]
  > publish = no
  > [experimental]
  > single-head-per-branch = yes
  > single-head-per-branch:public-changes-only = yes
  > EOF
  > hg phase -p :
  $ hg update 'desc("c_aG0")'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mkcommit c_dO0
  created new head
  $ hg log -G
  @  changeset:   9:8058fd35cc2b
  |  branch:      branch_A
  |  tag:         tip
  |  parent:      7:a33fb808fb4b
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c_dO0
  |
  | o  changeset:   8:49003e504178
  |/|  branch:      branch_A
  | |  parent:      7:a33fb808fb4b
  | |  parent:      3:840af1c6bc88
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     c_aI0
  | |
  o |  changeset:   7:a33fb808fb4b
  | |  branch:      branch_A
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     c_aG0
  | |
  o |  changeset:   6:99a2dc242c5d
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     c_dF1
  | |
  o |    changeset:   5:6ed1df20edb1
  |\ \   parent:      4:9bf953aa81f6
  | | |  parent:      2:286d02a6e2a2
  | | |  user:        test
  | | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | | |  summary:     c_dE0
  | | |
  | o |  changeset:   4:9bf953aa81f6
  | | |  parent:      1:134bc3852ad2
  | | |  user:        test
  | | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | | |  summary:     c_dD0
  | | |
  | | o  changeset:   3:840af1c6bc88
  | | |  branch:      branch_A
  | | |  parent:      0:ea207398892e
  | | |  user:        test
  | | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | | |  summary:     c_aC0
  | | |
  o | |  changeset:   2:286d02a6e2a2
  |/ /   user:        test
  | |    date:        Thu Jan 01 00:00:00 1970 +0000
  | |    summary:     c_dB0
  | |
  o |  changeset:   1:134bc3852ad2
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     c_dA0
  |
  o  changeset:   0:ea207398892e
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     ROOT
  
  $ hg phase -p .
  abort: rejecting multiple heads on branch "branch_A"
  (2 heads: 49003e504178 8058fd35cc2b)
  [255]