Added a comment: Weird behavior of git archive in combination with largefiles configuration

doc/git-annex-unannex/comment_6_d5a8450349b0383ec29d150420189937._comment

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+[[!comment format=mdwn
+ username="arnaud.legrand@e79f5d4cff79116f56388885021e8507bef18e12"
+ nickname="arnaud.legrand"
+ avatar="http://cdn.libravatar.org/avatar/143239914c3e3c1a374a7c244b56d73e"
+ subject="Weird behavior of git archive in combination with largefiles configuration"
+ date="2023-02-17T09:46:34Z"
+ content="""
+Hi,
+
+I'm preparing a lecture on how git annex can help research data
+management and I stumbled, when playing with `git-annex unannex`, on a
+strange behavior that I fail to understand nor to properly work around.
+When preparing for a public archive it may make sense to include
+**some** annexed files in the archive while it may be desirable to keep
+the symlinks for others (e.g., because they are already available from
+somewhere else). This is why I do not want to rely on the `git-annex
+export` mechanism that would replace the symlinks of all annexed files
+by their content.
+
+Instead, I `unannex` some of my files but surprisingly, depending on git
+annex configuration, their content may not be in the archive produced by
+`git archive`. Here is a minimal working example.
+
+``` shell
+DIR=/tmp/test
+chmod -Rf u+w $DIR; rm -rf $DIR ; mkdir -p $DIR; cd $DIR
+git init
+git annex init
+git config --local annex.largefiles 'largerthan=100kb and include=data/*'
+
+echo \"Hello\" > README
+git add README
+
+mkdir data/
+dd if=/dev/zero of=data/foo.dat bs=1M count=1 2>/dev/null
+git annex add data/foo.dat
+git commit -m \"Initial commit\"
+
+## git config --local annex.largefiles ''
+git annex unannex data/foo.dat && git add data/foo.dat && git commit -m \"Unannexing\" 
+git archive --format=tar.gz --prefix nobel_project/ -o ../archive.tgz HEAD
+
+tar zxf ../archive.tgz
+tree -s nobel_project/
+```
+
+``` example
+
+ Initialized empty Git repository in /tmp/test/.git/
+init  ok
+(recording state in git...)
+       add data/foo.dat
+31.98 KiB        14 MiB/s 0s100%  1 MiB           137 MiB/s 0s                                  ok
+(recording state in git...)
+[master (root-commit) 8fbb907] Initial commit
+ 2 files changed, 2 insertions(+)
+ create mode 100644 README
+ create mode 120000 data/foo.dat
+  unannex data/foo.dat ok
+(recording state in git...)
+[master da73fb0] Unannexing
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+)
+100644
+mnobel_project/
+├── [       4096]  data
+│   └── [        102]  foo.dat
+└── [          6]  README
+
+1 directory, 2 files
+```
+
+As you may see from the output, `foo.dat` is only 102 bytes whereas it
+should be 1MB. Instead the content of `foo.dat` is:
+
+``` shell
+cat nobel_project/data/foo.dat
+```
+
+``` example
+/annex/objects/SHA256E-s1048576--30e14955ebf1352266dc2ff8067e68104607e750abb9d3b36582b8af909fcb58.dat
+```
+
+But if I remove the `annex.largefiles` configuration (either upfront or
+right before calling `unannex`), everything works as expected, i.e., my
+archive comprises the content of the annexed file.
+
+Is this an expected behavior ? This is the kind of operation I typically
+do in a branch that I erase afterward but it (temporarily) messes my
+local git configuration, which I don't like, so I'm looking for a better
+workaround.
+
+Thanks for you amazing work,
+
+Arnaud
+
+"""]]