view tests/test-convert-cvs-detectmerge.t @ 45121:b6269741ed42

config: add option to control creation of empty successors during rewrite

The default for many history-rewriting commands (e.g. rebase and absorb) is
that changesets which would become empty are not created in the target branch.
This makes sense if the source branch consists of small fix-up changes. For
more advanced workflows that make heavy use of history-editing to create
curated patch series, dropping empty changesets is not as important or even
undesirable.

Some users want to keep the meta-history, e.g. to make finding comments in a
code review tool easier or to avoid that divergent bookmarks are created. For
that, obsmarkers from the (to-be) empty changeset to the changeset(s) that
already made the changes should be added. If a to-be empty changeset is pruned
without a successor, adding the obsmarkers is hard because the changeset has to
be found within the hidden part of the history.

If rebasing in TortoiseHg, it’s easy to miss the fact that the to-be empty
changeset was pruned. An empty changeset will function as a reminder that
obsmarkers should be added.

Martin von Zweigbergk mentioned another advantage. Stripping the successor will
de-obsolete the predecessor. If no (empty) successor is created, this won’t be
possible.

In the future, we may want to consider other behaviors, like e.g. creating the
empty successor, but pruning it right away. Therefore this configuration
accepts 'skip' and 'keep' instead of being a boolean configuration.

#require cvs no-root

Test config convert.cvsps.mergefrom config setting.
(Should test similar mergeto feature, but I don't understand it yet.)
Requires builtin cvsps.

  $ CVSROOT=`pwd`/cvsrepo
  $ export CVSROOT

  $ cvscall()
  > {
  >     cvs -f "$@"
  > }

output of 'cvs ci' varies unpredictably, so just discard it
XXX copied from test-convert-cvs-synthetic

  $ cvsci()
  > {
  >     sleep 1
  >     cvs -f ci "$@" > /dev/null
  > }

XXX copied from test-convert-cvs-synthetic

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > convert =
  > [convert]
  > cvsps.cache = 0
  > cvsps.mergefrom = \[MERGE from (\S+)\]
  > EOF

create cvs repository with one project

  $ cvscall -q -d "$CVSROOT" init
  $ mkdir cvsrepo/proj

populate cvs repository

  $ cvscall -Q co proj
  $ cd proj
  $ touch file1
  $ cvscall -Q add file1
  $ cvsci -m"add file1 on trunk"
  cvs commit: Examining .

create two release branches

  $ cvscall -q tag -b v1_0
  T file1
  $ cvscall -q tag -b v1_1
  T file1

modify file1 on branch v1_0

  $ cvscall -Q update -rv1_0
  $ sleep 1
  $ echo "change" >> file1
  $ cvsci -m"add text"
  cvs commit: Examining .

make unrelated change on v1_1

  $ cvscall -Q update -rv1_1
  $ touch unrelated
  $ cvscall -Q add unrelated
  $ cvsci -m"unrelated change"
  cvs commit: Examining .

merge file1 to v1_1

  $ cvscall -Q update -jv1_0
  RCS file: $TESTTMP/cvsrepo/proj/file1,v
  retrieving revision 1.1
  retrieving revision 1.1.2.1
  Merging differences between 1.1 and 1.1.2.1 into file1
  $ cvsci -m"add text [MERGE from v1_0]"
  cvs commit: Examining .

merge change to trunk

  $ cvscall -Q update -A
  $ cvscall -Q update -jv1_1
  RCS file: $TESTTMP/cvsrepo/proj/file1,v
  retrieving revision 1.1
  retrieving revision 1.1.4.1
  Merging differences between 1.1 and 1.1.4.1 into file1
  $ cvsci -m"add text [MERGE from v1_1]"
  cvs commit: Examining .

non-merged change on trunk

  $ echo "foo" > file2
  $ cvscall -Q add file2
  $ cvsci -m"add file2 on trunk" file2

this will create rev 1.3
change on trunk to backport

  $ echo "backport me" >> file1
  $ cvsci -m"add other text" file1
  $ cvscall log file1
  
  RCS file: $TESTTMP/cvsrepo/proj/file1,v
  Working file: file1
  head: 1.3
  branch:
  locks: strict
  access list:
  symbolic names:
  	v1_1: 1.1.0.4
  	v1_0: 1.1.0.2
  keyword substitution: kv
  total revisions: 5;	selected revisions: 5
  description:
  ----------------------------
  revision 1.3
  date: * (glob)
  add other text
  ----------------------------
  revision 1.2
  date: * (glob)
  add text [MERGE from v1_1]
  ----------------------------
  revision 1.1
  date: * (glob)
  branches:  1.1.2;  1.1.4;
  add file1 on trunk
  ----------------------------
  revision 1.1.4.1
  date: * (glob)
  add text [MERGE from v1_0]
  ----------------------------
  revision 1.1.2.1
  date: * (glob)
  add text
  =============================================================================

XXX how many ways are there to spell "trunk" with CVS?
backport trunk change to v1_1

  $ cvscall -Q update -rv1_1
  $ cvscall -Q update -j1.2 -j1.3 file1
  RCS file: $TESTTMP/cvsrepo/proj/file1,v
  retrieving revision 1.2
  retrieving revision 1.3
  Merging differences between 1.2 and 1.3 into file1
  $ cvsci -m"add other text [MERGE from HEAD]" file1

fix bug on v1_1, merge to trunk with error

  $ cvscall -Q update -rv1_1
  $ echo "merge forward" >> file1
  $ cvscall -Q tag unmerged
  $ cvsci -m"fix file1"
  cvs commit: Examining .
  $ cvscall -Q update -A
  $ cvscall -Q update -junmerged -jv1_1
  RCS file: $TESTTMP/cvsrepo/proj/file1,v
  retrieving revision 1.1.4.2
  retrieving revision 1.1.4.3
  Merging differences between 1.1.4.2 and 1.1.4.3 into file1

note the typo in the commit log message

  $ cvsci -m"fix file1 [MERGE from v1-1]"
  cvs commit: Examining .
  $ cvs -Q tag -d unmerged

convert to hg

  $ cd ..
  $ hg convert proj proj.hg
  initializing destination proj.hg repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  12 log entries
  creating changesets
  warning: CVS commit message references non-existent branch 'v1-1':
  fix file1 [MERGE from v1-1]
  10 changeset entries
  sorting...
  converting...
  9 add file1 on trunk
  8 unrelated change
  7 add text
  6 add text [MERGE from v1_0]
  5 add text [MERGE from v1_1]
  4 add file2 on trunk
  3 add other text
  2 add other text [MERGE from HEAD]
  1 fix file1
  0 fix file1 [MERGE from v1-1]

complete log

  $ template="{rev}: '{branches}' {desc}\n"
  $ hg -R proj.hg log --template="$template"
  9: '' fix file1 [MERGE from v1-1]
  8: 'v1_1' fix file1
  7: 'v1_1' add other text [MERGE from HEAD]
  6: '' add other text
  5: '' add file2 on trunk
  4: '' add text [MERGE from v1_1]
  3: 'v1_1' add text [MERGE from v1_0]
  2: 'v1_0' add text
  1: 'v1_1' unrelated change
  0: '' add file1 on trunk

graphical log

  $ hg -R proj.hg log -G --template="$template"
  o  9: '' fix file1 [MERGE from v1-1]
  |
  | o  8: 'v1_1' fix file1
  | |
  | o  7: 'v1_1' add other text [MERGE from HEAD]
  |/|
  o |  6: '' add other text
  | |
  o |  5: '' add file2 on trunk
  | |
  o |  4: '' add text [MERGE from v1_1]
  |\|
  | o    3: 'v1_1' add text [MERGE from v1_0]
  | |\
  +---o  2: 'v1_0' add text
  | |
  | o  1: 'v1_1' unrelated change
  |/
  o  0: '' add file1 on trunk