view tests/test-strip-cross.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

test stripping of filelogs where the linkrev doesn't always increase

  $ echo '[extensions]' >> $HGRCPATH
  $ echo 'strip =' >> $HGRCPATH
  $ hg init orig
  $ cd orig
  $ commit()
  > {
  >     hg up -qC null
  >     count=1
  >     for i in "$@"; do
  >         for f in $i; do
  >             echo $count > $f
  >         done
  >         count=`expr $count + 1`
  >     done
  >     hg commit -qAm "$*"
  > }

2 1 0 2 0 1 2

  $ commit '201 210'
  $ commit '102 120' '210'
  $ commit '021'
  $ commit '201' '021 120'
  $ commit '012 021' '102 201' '120 210'
  $ commit 'manifest-file'
  $ commit '102 120' '012 210' '021 201'
  $ commit '201 210' '021 120' '012 102'
  $ HGUSER=another-user; export HGUSER
  $ commit 'manifest-file'
  $ commit '012' 'manifest-file'
  $ cd ..
  $ hg clone -q -U -r -1 -r -2 -r -3 -r -4 -r -6 orig crossed
  $ cd crossed
  $ hg debugindex --manifest
     rev linkrev nodeid       p1           p2
       0       0 6f105cbb914d 000000000000 000000000000
       1       3 1b55917b3699 000000000000 000000000000
       2       1 8f3d04e263e5 000000000000 000000000000
       3       2 f0ef8726ac4f 000000000000 000000000000
       4       4 0b76e38b4070 000000000000 000000000000

  $ for i in 012 021 102 120 201 210 manifest-file; do
  >     echo $i
  >     hg debugindex $i
  >     echo
  > done
  012
     rev linkrev nodeid       p1           p2
       0       0 b8e02f643373 000000000000 000000000000
       1       1 5d9299349fc0 000000000000 000000000000
       2       2 2661d26c6496 000000000000 000000000000
  
  021
     rev linkrev nodeid       p1           p2
       0       0 b8e02f643373 000000000000 000000000000
       1       2 5d9299349fc0 000000000000 000000000000
       2       1 2661d26c6496 000000000000 000000000000
  
  102
     rev linkrev nodeid       p1           p2
       0       1 b8e02f643373 000000000000 000000000000
       1       0 5d9299349fc0 000000000000 000000000000
       2       2 2661d26c6496 000000000000 000000000000
  
  120
     rev linkrev nodeid       p1           p2
       0       1 b8e02f643373 000000000000 000000000000
       1       2 5d9299349fc0 000000000000 000000000000
       2       0 2661d26c6496 000000000000 000000000000
  
  201
     rev linkrev nodeid       p1           p2
       0       2 b8e02f643373 000000000000 000000000000
       1       0 5d9299349fc0 000000000000 000000000000
       2       1 2661d26c6496 000000000000 000000000000
  
  210
     rev linkrev nodeid       p1           p2
       0       2 b8e02f643373 000000000000 000000000000
       1       1 5d9299349fc0 000000000000 000000000000
       2       0 2661d26c6496 000000000000 000000000000
  
  manifest-file
     rev linkrev nodeid       p1           p2
       0       3 b8e02f643373 000000000000 000000000000
       1       4 5d9299349fc0 000000000000 000000000000
  
  $ cd ..
  $ for i in 0 1 2 3 4; do
  >     hg clone -q -U --pull crossed $i
  >     echo "% Trying to strip revision $i"
  >     hg --cwd $i strip $i
  >     echo "% Verifying"
  >     hg --cwd $i verify
  >     echo
  > done
  % Trying to strip revision 0
  saved backup bundle to $TESTTMP/0/.hg/strip-backup/*-backup.hg (glob)
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 4 changesets with 15 changes to 7 files
  
  % Trying to strip revision 1
  saved backup bundle to $TESTTMP/1/.hg/strip-backup/*-backup.hg (glob)
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 4 changesets with 14 changes to 7 files
  
  % Trying to strip revision 2
  saved backup bundle to $TESTTMP/2/.hg/strip-backup/*-backup.hg (glob)
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 4 changesets with 14 changes to 7 files
  
  % Trying to strip revision 3
  saved backup bundle to $TESTTMP/3/.hg/strip-backup/*-backup.hg (glob)
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 4 changesets with 19 changes to 7 files
  
  % Trying to strip revision 4
  saved backup bundle to $TESTTMP/4/.hg/strip-backup/*-backup.hg (glob)
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 4 changesets with 19 changes to 7 files