[darcs-devel] [issue1519] Surprising behaviour of darcs mv

[Lele Gaifax]

New submission from Lele Gaifax <lele at nautilus.homeip.net>:

Hi all,

yesterday I did a little reorg of one project, moving stuff around. In
particular, I had a sub/subfolder that I moved to the top level, and a
few other files moved into it as well.

Trying to distill a simple recipe to trigger the behaviour, I was even
more surprised to come up with two *very* similar scripts that produce
different output...

This first script:

    darcs --version
    mkdir p
    cd p
    darcs init
    mkdir -p folder/subfolder
    touch folder/subfolder/file_a
    touch folder/subfolder/file_b
    mkdir other
    touch other/file_c
    darcs add --recursive folder other
    darcs record -a -m "1st"
    mkdir another
    touch another/file_z
    darcs add --recursive another
    darcs record -a -m "2nd"
    darcs mv folder/subfolder promoted
    darcs mv other/file_c promoted/new_name
    darcs mv another/file_z promoted
    darcs whatsnew -s
    darcs record -a -m "3rd"
    darcs changes -s --last=1
    cd ..
    rm -rf p

outputs this:

    $ sh -x pp.sh
    + darcs --version
    2.3.0 (release)
    + mkdir p
    + cd p
    + darcs init
    + mkdir -p folder/subfolder
    + touch folder/subfolder/file_a
    + touch folder/subfolder/file_b
    + mkdir other
    + touch other/file_c
    + darcs add --recursive folder other
    + darcs record -a -m 1st
    Finished recording patch '1st'
    + mkdir another
    + touch another/file_z
    + darcs add --recursive another
    + darcs record -a -m 2nd
    Finished recording patch '2nd'
    + darcs mv folder/subfolder promoted
    + darcs mv other/file_c promoted/new_name
    + darcs mv another/file_z promoted
    + darcs whatsnew -s
     ./another/file_z -> ./folder/subfolder/file_z
     ./folder/subfolder -> ./promoted
     ./other/file_c -> ./promoted/new_name
    + darcs record -a -m 3rd
    Finished recording patch '3rd'
    + darcs changes -s --last=1
    Thu Aug 13 11:16:31 CEST 2009  lele at nautilus.homeip.net
      * 3rd

         ./another/file_z -> ./folder/subfolder/file_z
         ./folder/subfolder -> ./promoted
         ./other/file_c -> ./promoted/new_name
    + cd ..
    + rm -rf p

And you can see the two different ways darcs handled the move of
"another/file_z" and "other/file_c" into the renamed folder.

This other script, that AFAICS differs from the first *only* on the
path names (what was "another" in the first is "third" here...):

    darcs --version
    mkdir p
    cd p
    darcs init
    mkdir -p folder/subfolder
    touch folder/subfolder/file_a
    touch folder/subfolder/file_b
    mkdir other
    touch other/file_c
    darcs add --recursive folder other
    darcs record -a -m "1st"
    mkdir third
    touch third/file_z
    darcs add --recursive third
    darcs record -a -m "2nd"
    darcs mv folder/subfolder promoted
    darcs mv other/file_c promoted/new_name
    darcs mv third/file_z promoted
    darcs whatsnew -s
    darcs record -a -m "3rd"
    darcs changes -s --last=1
    cd ..
    rm -rf p

does not produce the same:

    $ sh -x p.sh
    + darcs --version
    2.3.0 (release)
    + mkdir p
    + cd p
    + darcs init
    + mkdir -p folder/subfolder
    + touch folder/subfolder/file_a
    + touch folder/subfolder/file_b
    + mkdir other
    + touch other/file_c
    + darcs add --recursive folder other
    + darcs record -a -m 1st
    Finished recording patch '1st'
    + mkdir third
    + touch third/file_z
    + darcs add --recursive third
    + darcs record -a -m 2nd
    Finished recording patch '2nd'
    + darcs mv folder/subfolder promoted
    + darcs mv other/file_c promoted/new_name
    + darcs mv third/file_z promoted
    + darcs whatsnew -s
     ./folder/subfolder -> ./promoted
     ./other/file_c -> ./promoted/new_name
     ./third/file_z -> ./promoted/file_z
    + darcs record -a -m 3rd
    Finished recording patch '3rd'
    + darcs changes -s --last=1
    Thu Aug 13 11:17:16 CEST 2009  lele at nautilus.homeip.net
      * 3rd

         ./folder/subfolder -> ./promoted
         ./other/file_c -> ./promoted/new_name
         ./third/file_z -> ./promoted/file_z
    + cd ..
    + rm -rf p

and actually this is what I was expecting to see...

Just to be picky:

    $ diff -u pp.sh p.sh
    --- pp.sh       2009-08-13 11:15:47.163840847 +0200
    +++ p.sh        2009-08-13 11:12:07.872139599 +0200
    @@ -9,13 +9,13 @@
     touch other/file_c
     darcs add --recursive folder other
     darcs record -a -m "1st"
    -mkdir another
    -touch another/file_z
    -darcs add --recursive another
    +mkdir third
    +touch third/file_z
    +darcs add --recursive third
     darcs record -a -m "2nd"
     darcs mv folder/subfolder promoted
     darcs mv other/file_c promoted/new_name
    -darcs mv another/file_z promoted
    +darcs mv third/file_z promoted
     darcs whatsnew -s
     darcs record -a -m "3rd"
     darcs changes -s --last=1

This is not a problem at all of course, after all everything is going
ok, but I tag this as "problematic", in the sense that tools like
tailor and trac-darcs have to do tricky dance to understand what's
going on.

thank you,
ciao, lele.
-- 
nickname: Lele Gaifax    | Quando vivrò di quello che ho pensato ieri
real: Emanuele Gaifas    | comincerò ad aver paura di chi mi copia.
lele at nautilus.homeip.net |                 -- Fortunato Depero, 1929.

----------
messages: 8124
nosy: dmitry.kurochkin, kowey, lele, simon, thorkilnaur
status: unread
title: Surprising behaviour of darcs mv

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Darcs bug tracker <bugs at darcs.net>
<http://bugs.darcs.net/issue1519>
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