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Differential D8939

tests: add criss cross merging tests whose behavior need to be fixed
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Authored by pulkit on Aug 24 2020, 10:14 AM.

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marmoute
Group Reviewers
hg-reviewers
Commits
rHG9bd60ec60601: tests: add criss cross merging tests whose behavior need to be fixed
Summary

Merging two changesets can mark a file as removed post merge. However, in some
cases, a user might not want to remove that file and they revert the removal
back and commit the merge. All this works perfectly well.

However, when we do criss-cross merges with such merge where user explicitly
choose to revert the removal with one where another user choose the removal,
we does not get any conflict.

The intent here is conflicting and merge should result in conflicts. One user
merged and want to keep the file while other user merged and want to remove the
file. Merging those merges should result in conflicts.

This patch adds test cases for these cases.

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Event Timeline

pulkit created this revision.Aug 24 2020, 10:14 AM
marmoute added a subscriber: marmoute.Aug 26 2020, 12:54 PM

How does this related to the test I handed to you 10 day ago. Is this testing a new case where we could get criss cross merge to behave right or is this a variation of the one I wrote?

pulkit retitled this revision from tests: add more criss-cross merging tests where behavior needs to be fixed to tests: add criss cross merging tests whose behavior need to be fixed.Aug 27 2020, 5:37 AM
pulkit edited the summary of this revision. (Show Details)
pulkit updated this revision to Diff 22472.
pulkit added a comment.Sep 9 2020, 10:08 AM
In D8939#134076, @marmoute wrote:

How does this related to the test I handed to you 10 day ago. Is this testing a new case where we could get criss cross merge to behave right or is this a variation of the one I wrote?

Updated to use the same one.

pulkit added a comment.Sep 9 2020, 10:11 AM

For reviewers: I admit that this series is going to be not-easy to review. It took me quite few time to understand what the issue is. The series except for this patch, starts with minor improvements to merge code and later on try to fix bugs related to criss cross merging. I will be glad to have a video call if anyone needs help with understanding the series.

marmoute accepted this revision.Sep 11 2020, 4:52 AM

thanks for the extensive documentation.

marmoute added a commit: rHG9bd60ec60601: tests: add criss cross merging tests whose behavior need to be fixed.Sep 16 2020, 7:49 AM
This revision was not accepted when it landed; it landed in state Needs Review.
Closed by commit rHG9bd60ec60601: tests: add criss cross merging tests whose behavior need to be fixed (authored by marmoute). · Explain Why
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mtests/test-merge-criss-cross.t (222 lines)

Diff 22472

tests/test-merge-criss-cross.t

d1/a: other deleted -> r d1/a: other deleted -> r
removing d1/a removing d1/a
d1/b: other deleted -> r d1/b: other deleted -> r
removing d1/b removing d1/b
d2/b: remote created -> g d2/b: remote created -> g
getting d2/b getting d2/b
1 files updated, 0 files merged, 2 files removed, 0 files unresolved 1 files updated, 0 files merged, 2 files removed, 0 files unresolved
(branch merge, don't forget to commit) (branch merge, don't forget to commit)
Check that removal reversion does not go unotified
==================================================
On a merge, a file can be removed and user can revert that removal. This means
user has made an explicit choice of keeping the file or reverting the removal
even though the merge algo wanted to remove it.
Based on this, when we do criss cross merges, merge algorithm should not again
choose to remove the file as in one of the merges, user made an explicit choice
to revert the removal.
Following test cases demonstrate how merge algo does not take in account
explicit choices made by users to revert the removal and on criss-cross merging
removes the file again.
"Simple" case where the filenode changes
----------------------------------------
$ cd ..
$ hg init criss-cross-merge-reversal-with-update
$ cd criss-cross-merge-reversal-with-update
$ echo the-file > the-file
$ echo other-file > other-file
$ hg add the-file other-file
$ hg ci -m 'root-commit'
$ echo foo >> the-file
$ echo bar >> other-file
$ hg ci -m 'updating-both-file'
$ hg up 'desc("root-commit")'
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg rm the-file
$ hg ci -m 'delete-the-file'
created new head
$ hg log -G -T '{node|short} {desc}\n'
@ 7801bc9b9899 delete-the-file
|
| o 9b610631ab29 updating-both-file
|/
o 955800955977 root-commit
Do all the merge combination (from the deleted or the update side × keeping and deleting the file
$ hg update 'desc("delete-the-file")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("updating-both-file")' -t :local
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merge-deleting-the-file-from-deleted"
$ hg manifest
other-file
$ hg update 'desc("updating-both-file")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("delete-the-file")' -t :other
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merge-deleting-the-file-from-updated"
created new head
$ hg manifest
other-file
$ hg update 'desc("delete-the-file")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("updating-both-file")' -t :other
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merge-keeping-the-file-from-deleted"
created new head
$ hg manifest
other-file
the-file
$ hg update 'desc("updating-both-file")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("delete-the-file")' -t :local
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merge-keeping-the-file-from-updated"
created new head
$ hg manifest
other-file
the-file
There the resulting merge together (leading to criss cross situation). Check
the conflict is properly detected.
(merging two deletion together → no conflict)
$ hg update --clean 'desc("merge-deleting-the-file-from-deleted")'
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 'desc("merge-deleting-the-file-from-updated")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-deleting-the-file-from-deleted")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-keeping-the-file-from-deleted")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
the-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-deleting-the-file-from-deleted")'
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 'desc("merge-keeping-the-file-from-updated")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
the-file
(merging two deletion together → no conflict)
$ hg update --clean 'desc("merge-deleting-the-file-from-updated")'
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 'desc("merge-deleting-the-file-from-deleted")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-deleting-the-file-from-updated")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-keeping-the-file-from-deleted")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
the-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-deleting-the-file-from-updated")'
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 'desc("merge-keeping-the-file-from-updated")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
the-file
(merging two "keeping" together → no conflict)
$ hg update --clean 'desc("merge-keeping-the-file-from-updated")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-keeping-the-file-from-deleted")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
the-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-keeping-the-file-from-updated")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-deleted-the-file-from-deleted")'
abort: empty revision set
[255]
$ ls -1
other-file
the-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-keeping-the-file-from-updated")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-deleting-the-file-from-updated")'
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
(merging two "keeping" together → no conflict)
$ hg update --clean 'desc("merge-keeping-the-file-from-deleted")'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-keeping-the-file-from-updated")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file
the-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-keeping-the-file-from-deleted")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-deleted-the-file-from-deleted")'
abort: empty revision set
[255]
$ ls -1
other-file
the-file
(merging a deletion with keeping → conflict)
BROKEN: this should result in conflict
$ hg update --clean 'desc("merge-keeping-the-file-from-deleted")'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge 'desc("merge-deleting-the-file-from-updated")'
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ ls -1
other-file