#!/bin/sh

set -e

cwd=`pwd`
basename=`basename $0`
scratch_area="`echo $basename | sed -e s/\.sh$//`"
repos=$scratch_area/repos
trunk=$scratch_area/trunk
branch=$scratch_area/branch
feature1=$scratch_area/feature1
feature2=$scratch_area/feature2
rebase=$scratch_area/rebase
trunk_url=file:///$cwd/$repos/trunk
branch_url=file:///$cwd/$repos/branches/firstbranch
feature1_url=file:///$cwd/$repos/branches/feature1
feature2_url=file:///$cwd/$repos/branches/feature2
rebase_url=file:///$cwd/$repos/branches/rebase

set -x

rm -rf $scratch_area
mkdir -p $scratch_area

mkdir -p $trunk
echo alpha > $trunk/alpha
echo beta > $trunk/beta
mkdir $trunk/gamma
echo delta > $trunk/gamma/delta
mkdir $trunk/epsilon
echo zeta > $trunk/epsilon/zeta

svnadmin create $cwd/$repos
svn import $trunk $trunk_url -m "importing project tree"
svn copy --parents $trunk_url $branch_url -m "creating branch"
rm -rf $trunk
svn checkout $trunk_url $trunk
svn checkout $trunk_url ${trunk}2
svn checkout $branch_url $branch

# Create some mergeinfo using the branch we just created.
# Make some changes in the branch, reintegrate and delete it.
# This is done only to have some prior merge history in mergeinfo.
# It may or may not be relevant to the problem.
echo aaa >> $branch/alpha
svn ci $branch -m "change branch"

svn up $trunk
svn merge --reintegrate $branch_url $trunk
svn ci $trunk -m "reintegrated branch"
svn rm $branch_url -m "remove branch"
rm -rf $branch

# Create a feature1 branch
svn cp $trunk_url $feature1_url -m "create feature1 branch"
svn co $feature1_url $feature1
echo bbb >> $feature1/beta
svn ci $feature1 -m "work on feature1"

# Do something on trunk
echo zzz >> $trunk/epsilon/zeta
svn ci $trunk -m "some work on trunk"

# Sync feature1 branch to trunk
svn up $feature1
svn merge $trunk_url $feature1
svn ci $feature1 -m "sync with trunk"

# Create a feature2 branch, do some work on it
svn cp $trunk_url $feature2_url -m "create feature2 branch"
svn co $feature2_url $feature2
echo aaaa >> $feature2/alpha
svn ci $feature2 -m "work on feature2"

# Reintegrate the feature2 branch
svn up $trunk
svn merge --reintegrate $feature2_url $trunk
svn ci $trunk -m "reintegrate bugfix from feature2 branch"

# Keep the feature2 branch alive, we need to do more work still.
# This creates mergeinfo on the feature2 branch for trunk.
svn up $feature2
svn merge -c `svnlook youngest $repos` --record-only $trunk_url $feature2
svn ci $feature2 -m "block reintegration revision"

# Sync the feature2 branch with trunk.
# This creates more mergeinfo on the feature2 branch for trunk (though
# nothing is actually merged).
svn up $feature2
svn merge $trunk_url $feature2
svn ci $feature2 -m "sync with trunk"

# Sync the feature1 branch with trunk.
svn up $feature1
svn merge $trunk_url $feature1
svn ci $feature1 -m "sync with trunk"

rebase_rev=`svnlook youngest $repos`

# Management decided that feature1 should be merged with feature2.
# feature1 is based on the code base of trunk, so we'll have some
# integration work to do to merge with feature2.
# So do a 'rebase' of the feature1 -- this means merging the diff
# trunk->feature1 into the feature2 branch.
svn up $feature2
svn merge $trunk_url@$rebase_rev $feature1_url $feature2

# Ooops... Why does the mergeinfo for trunk get reverted?
# Without it, we cannot sync the feature2 branch to trunk anymore :(
svn diff $feature2
svn pg -v -R svn:mergeinfo $feature2

# Alternative case, with a temporary integration branch, same problem:

#svn cp $feature2_url $rebase_url -m "create rebase branch"
#svn co $rebase_url $rebase
#svn merge $trunk_url@$rebase_rev $feature1_url $rebase
#svn diff $rebase
#svn pg -v -R svn:mergeinfo $rebase