From: "Stefan Beller" <redacted>

On Mon, Apr 24, 2017 at 1:06 AM, Orgad Shaneh [off-list ref] wrote:

quoted

Hi,

I've noticed a strange behavior with submodule/content conflict. My
current Git version is 2.12.2, but the problem exists since I
remember.

Branch A has a submodule.
In branch B which diverged from A, I replaced the submodule with its 
contents.

Now, every time I merge A into B, and A had changed the submodule
reference, all the files inside the ex-submodule directory in B are
being "re-added".

Moreover, aborting the merge prints an error, but seems to work
nevertheless, and if I run git reset --hard all the files in that
directory are actually written to the disk, even though they haven't
changed at all.

This is almost the same as just reported by 'vvs' [1] 
https://public-inbox.org/git/CAM1zWBtfgHT=pT0pidQo1HD=DfrXLG3gNaUvs0vZKvYfG1BHFw@mail.gmail.com/, 
originally on the 'git user' list 
https://groups.google.com/forum/?hl=en#!topic/git-users/9ziZ6yq-BfU

It also has a similarity to 
https://public-inbox.org/git/1492287435.14812.2.camel@gmail.com/  regarding 
how checkout operates.

It does feel as if there are two slightly different optimisations that could 
be used when the desired file pre-exists in the worktree, but isn't 
immediately known to the index.

quoted

When the submodule is small, it might be ok. But in my project we have
a huge submodule with ~16K files, and on each merge all the files are
listed, and even mixed reset takes several minutes.

That sounds like a wait that is not wanted!

quoted

A similar bug report
https://public-inbox.org/git/CAG0BQX=wvpkJ=PQWV-NbmhuPV8yzvd_KYKzJmsfWq9xStZ2bnQ@mail.gmail.com/

"checkout --recurse-submodules" (as mentioned in that report)
made it into Git by now, but this bug goes unfixed, still.

quoted

The following script demonstrates this:
#!/bin/sh

rm -rf super sub
mkdir sub
cd sub
git init
touch foo
git add foo
git commit -m 'Initial commit'
mkdir ../super; cd ../super
git init
git submodule add ../sub
touch foo; git add foo sub
git commit -m 'Initial commit'
git checkout -b update-sub
git update-index --cacheinfo 
160000,aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,sub
git commit -m 'Update submodule'
git checkout -b remove-sub HEAD^
git rm sub
mkdir sub
touch sub/foo sub/bar
git add sub
git commit -m 'Replaced submodule with contents'
git checkout -b remove-2 HEAD^
git merge --no-ff remove-sub
git merge update-sub
# Adding sub/foo
# Adding sub/bar
# CONFLICT (modify/delete): sub deleted in HEAD and modified in
update-sub. Version update-sub of sub left in tree at sub~update-sub.
# Automatic merge failed; fix conflicts and then commit the result.
git merge --abort
# error: 'sub' appears as both a file and as a directory
# error: sub: cannot drop to stage #0

- Orgad

--
Philip