#! /bin/bash

# This script demonstrates a bug in git where it reports
#
#   The following submodule paths contain changes that can
#   not be found on any remote:
#
# for a submodule that is clean and pushed.
#
# Create an empty directory, put this script in it
# and run the script.
#
# Carlo Wood, 2017/01/29

# Clean a possible previous run:
rm -rf parent remote.parent remote.subm

REMOTE_BASE="$(pwd)"

# Create a 'remote' for the submodule 'subm'.
mkdir remote.subm
pushd remote.subm
git init --bare
popd

# Create a 'remote' for the 'parent' repository.
mkdir remote.parent
pushd remote.parent
git init --bare
popd

# Create initial parent/subm directory structore.
mkdir -p parent/subm

# Create an initial subm git repository.
pushd parent/subm
git init
git remote add local "$REMOTE_BASE/remote.subm"
touch s ; git add s
git commit -m 'Initial commit.'
git push --set-upstream local master
popd

# Create an initial parent git repository with subm as submodule
# and push.recurseSubmodules = on-demand.
pushd parent
git init
git config push.recurseSubmodules on-demand
git remote add local "$REMOTE_BASE/remote.parent"
touch p ; git add p
git submodule add "$REMOTE_BASE/remote.subm subm"
git add .gitmodules subm
git commit -m 'Initial commit.'
git push --set-upstream local master
popd

# Do some commit in subm, but do not push it to the remote.
pushd parent/subm
echo "My frist commit." > s
git commit -a -m 'Change s'
popd

# Add the subm hash to the parent.
pushd parent
git add subm
git commit -m 'Updated subm.'
popd

# Amend the commit in subm (and optionally push it).
pushd parent/subm
echo "My first commit." > s
git commit -a --amend -m 'Change s'
popd

# Correct that in the parent too:
pushd parent
git add subm
git commit -m 'Updated subm.'
popd

# At this point nothing was published yes, so the
# amend shouldn't have caused a problem. But it did.
pushd parent
git push
popd

echo "THE ABOVE ERROR CAN NOW BE REPRODUCED INDEFINITELY,"
echo "FOR EXAMPLE, DO:"
echo "cd parent/subm"
echo "git push"
echo "cd .."
echo "git push"