( )⚙ D6190 tests: better document the graft copy case

This is an archive of the discontinued Mercurial Phabricator instance.

Differential D6190

tests: better document the graft copy case
ClosedPublic

Authored by martinvonz on Apr 3 2019, 12:53 PM.

Details

Reviewers
None
Group Reviewers
hg-reviewers
Commits
rHGb9e5f3853a97: tests: better document the graft copy case

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

martinvonz created this revision.Apr 3 2019, 12:53 PM
marmoute added a subscriber: marmoute.Apr 3 2019, 2:26 PM

Thanks looks good to me. Thanks for clarifying the table.

Closed by commit rHGb9e5f3853a97: tests: better document the graft copy case (authored by martinvonz). · Explain WhyApr 3 2019, 7:07 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mtests/test-graft.t (17 lines)

Diff 14647

tests/test-graft.t

|/ |/
o 0 o 0
Graft from behind a move or rename Graft from behind a move or rename
================================== ==================================
NOTE: This is affected by issue5343, and will need updating when it's fixed NOTE: This is affected by issue5343, and will need updating when it's fixed
Possible cases during a regular graft (when ca is between cta and c2): Consider this topology for a regular graft:
o c1
|
| o c2
| |
| o ca # stands for "common ancestor"
|/
o cta # stands for "common topological ancestor"
Note that in issue5343, ca==cta.
The following table shows the possible cases. Here, "x->y" and, equivalently,
"y<-x", where x is an ancestor of y, means that some copy happened from x to y.
name | c1<-cta | cta<->ca | ca->c2 name | c1<-cta | cta<->ca | ca->c2
A.0 | | | A.0 | | |
A.1 | X | | A.1 | X | |
A.2 | | X | A.2 | | X |
A.3 | | | X A.3 | | | X
A.4 | X | X | A.4 | X | X |
A.5 | X | | X A.5 | X | | X
appropriate side of the incomplete divergence, and the result is recorded as a appropriate side of the incomplete divergence, and the result is recorded as a
divergence. The code doesn't distinguish at all between these two cases, since divergence. The code doesn't distinguish at all between these two cases, since
the end result of them is the same: an incomplete divergence joined with an the end result of them is the same: an incomplete divergence joined with an
incomplete rename into a divergence. incomplete rename into a divergence.
Finally, A.6 records a divergence entirely in the c2 pass. Finally, A.6 records a divergence entirely in the c2 pass.
A.4 has a degenerate case a<-b<-a->a, where checkcopies isn't needed at all. A.4 has a degenerate case a<-b<-a->a, where checkcopies isn't needed at all.
A.5 has a special case a<-b<-b->a, which is treated like a<-b->a in a merge. A.5 has a special case a<-b<-b->a, which is treated like a<-b->a in a merge.
A.5 has issue5343 as a special case.
TODO: add test coverage for A.5
A.6 has a special case a<-a<-b->a. Here, checkcopies will find a spurious A.6 has a special case a<-a<-b->a. Here, checkcopies will find a spurious
incomplete divergence, which is in fact complete. This is handled later in incomplete divergence, which is in fact complete. This is handled later in
mergecopies. mergecopies.
A.7 has 4 special cases: a<-b<-a->b (the "ping-pong" case), a<-b<-c->b, A.7 has 4 special cases: a<-b<-a->b (the "ping-pong" case), a<-b<-c->b,
a<-b<-a->c and a<-b<-c->a. Of these, only the "ping-pong" case is interesting, a<-b<-a->c and a<-b<-c->a. Of these, only the "ping-pong" case is interesting,
the others are fairly trivial (a<-b<-c->b and a<-b<-a->c proceed like the base the others are fairly trivial (a<-b<-c->b and a<-b<-a->c proceed like the base
case, a<-b<-c->a is treated the same as a<-b<-b->a). case, a<-b<-c->a is treated the same as a<-b<-b->a).