bzr-fast-export exports rm+mv incorrectly

[Jonas]

if doing
bzr rm a
bzr mv b a
commit

then bzr-fast-export will export a mv followed by a rm, causing a to vanish in total
(btw, bzr diff -c also shows them in "opposite" order)

[Jonas (jonas-annica)]

Proposed patch.
Move delete-handling earlier in emit_commit

[Ian Clatworthy (ian-clatworthy)]

Patch applied to trunk and available in rev 87.

[Jonas (jonas-annica)]

hmm..found a bug in my patch...
will try to write another variant...
but I don't know the internals, so it's really just guess work

/Jonas

[Jonas (jonas-annica)]

Found case where current patch does not work

[Jonas (jonas-annica)]

new variant of patch

[Gabriel de Perthuis (g2p)]

The current code (r87) is also screwy and can't import ipython (these revisions: http://bazaar.launchpad.net/~ipython-dev/ipython/trunk/revision/1004 http://bazaar.launchpad.net/~ipython-dev/ipython/trunk/revision/1001.1.3 http://bazaar.launchpad.net/~ipython-dev/ipython/trunk/revision/1001.1.1 ).

Here is a test case:

bzr init
mkdir fools
touch fools/FOO
bzr add fools/FOO
bzr commit -m Initial
bzr mv fools/FOO .
bzr rm fools
bzr commit -m MvRm

# Fails
git init; ~/var/co/bzr/bzr-fastimport/exporters/bzr-fast-export.py . |git fast-import

# Exported data
/home/g2p/var/co/bzr/bzr-fastimport/exporters/bzr-fast-export.py .
*** BzrFastExport: Exported 0 commits; forcing checkpoint
checkpoint
commit refs/heads/tmp
mark :1
committer <whomever> 1224661056 +0200
data 7
Initial
M 644 inline fools/FOO
data 0

commit refs/heads/master
mark :2
committer <whomever> 1224661106 +0200
data 4
MvRm
from :1
D fools
R fools/FOO FOO

# When what should be exported is:
R fools/FOO FOO
D fools

[Gabriel de Perthuis (g2p)]

Reopen, see second test case.

[Gabriel de Perthuis (g2p)]

Tree.changes_from is lossy (the docs hint at it as well: http://bazaar-vcs.org/Integrating_with_Bazaar ). I'll try to rewrite this using Tree.iter_changes .

[Gabriel de Perthuis (g2p)]

I've rewritten the exporter to stream directly the iter_changes operations. This does fix my testcase, which was with the exporter being too much involved with directory moves.

But these are not the correct semantics yet, because iter_changes appears to give an unordered set of changes.

For example (this bug's first testcase), it returns things like:
R a b
D b
Which, serialized, should become
D b
R a b

Another problematic situation is (#285175):
R b a
R a b
Which needs an intermediary to be serialized
R b t
R a b
R t a

[Jonas (jonas-annica)]

See:

https://bugs.launchpad.net/bzr-fastimport/+bug/285175

Furthermore, I don't know of any case not working with my latest patch
on this bug

Do you ?

/Jonas

--- Den tors 2008-10-23 skrev Gabriel de Perthuis <email address hidden>:

> Från: Gabriel de Perthuis <email address hidden>
> Ämne: [Bug 268933] Re: bzr-fast-export exports rm+mv incorrectly
> Till: <email address hidden>
> Datum: torsdag 23 oktober 2008 01.29
> I've rewritten the exporter to stream directly the
> iter_changes
> operations. This does fix my testcase, which was with the
> exporter being
> too much involved with directory moves.
>
> But these are not the correct semantics yet, because
> iter_changes
> appears to give an unordered set of changes.
>
> For example (this bug's first testcase), it returns
> things like:
> R a b
> D b
> Which, serialized, should become
> D b
> R a b
>
> Another problematic situation is (#285175):
> R b a
> R a b
> Which needs an intermediary to be serialized
> R b t
> R a b
> R t a
>
>
> ** Attachment added: "WIP patch"
>
> http://launchpadlibrarian.net/18808271/iter_changes.patch
>
> --
> bzr-fast-export exports rm+mv incorrectly
> https://bugs.launchpad.net/bugs/268933
> You received this bug notification because you are a direct
> subscriber
> of the bug.
>
> Status in Bazaar Fast Import Plugin: Confirmed
>
> Bug description:
> if doing
> bzr rm a
> bzr mv b a
> commit
>
> then bzr-fast-export will export a mv followed by a rm,
> causing a to vanish in total
> (btw, bzr diff -c also shows them in "opposite"
> order)

      __________________________________________________________
Låna pengar utan säkerhet. Jämför vilkor online hos Kelkoo.
http://www.kelkoo.se/c-100390123-lan-utan-sakerhet.html?partnerId=96915014

[Gabriel de Perthuis (g2p)]

I've tested your latest patch.
My testcase ( https://bugs.launchpad.net/bzr-fastimport/+bug/268933/comments/7 ) still fails, due to the way directory moves are handled.
I'll see if I can work on top of your patch. Anyway, I'll check with the testcases of both bugs.

[Chow Loong Jin (hyperair)]

I believe lp:tangerine also suffers from this. A previous version of bzr-fast-export I grabbed from somewhere I don't remember appears to handle it correctly though.

[Chow Loong Jin (hyperair)]

Or not. Poking in git fast-import log shows that it's more similar to bug #219042 instead. Sorry for the noise.