Add a script to combine imported Mandriva git reposo with Mageia SVN history.

This script helps to automate a task that is, in a large part, manual.

It takes the git-svn repostitory from the Mandrvia import and guides
you through the task of adapting it and importing the Mageia SVN history
on top.

You first have to pick the trunk revision at which you want to reset the history.
This should be the point in time when Mageia imported the sources.

It will then help you find the correct Mandriva SVN revision to use as your
starting point. It will then synthesize a commit to reset the repository
at the same state as the Mageia subversion at the chosen revision. This
should result in minimal file churn (i.e. it's should be mostly
s/Mandriva/Magiea/ and a few other tweaks). In an ideal world it would contain
no other fixes but in order to minimise bogus git-blame results it should
avoid big 'delete-then-add' commits.

Once this is done, the script then synthesises the internal git-svn metadata
and tricks git-svn into continuing the import.

It will likely break if any branches/tags have the same name in Mageia
as existed in Mandriva. Fingers crossed that doesn't happen :)

1 files changed, 158 insertions, 0 deletions

diff --git a/scripts/mageia-reset-and-import.sh b/scripts/mageia-reset-and-import.sh
new file mode 100755
index 0000000..337d6df
--- /dev/null
+++ b/scripts/mageia-reset-and-import.sh
@@ -0,0 +1,158 @@
+#!/bin/bash
+
+NEWSVNURL="file:///home/colin/svn-git/soft"
+SOFTWARE=
+if [ -d ".git" -a -f ".git/config" -a -f ".git/svn/.metadata" ]; then
+  SOFTWARE=$(grep "fetch = " .git/config | cut -d'=' -f2- | cut -d':' -f1 | sed 's,/trunk,,' | trim)
+fi
+
+if [ -z "$SOFTWARE" ]; then
+  echo "You must run this in a git-svn clone folder." >&2
+  exit 1
+fi
+
+if [ -d ../$SOFTWARE.git ]; then
+  echo "It seems the converted git repository already exists (../$SOFTWARE.git)"
+  exit 1
+fi
+
+echo -n "Finding UUID for SVN Repository $NEWSVNURL... "
+NEWSVNUUID=$(svn info $NEWSVNURL | grep "^Repository UUID:" | sed 's/Repository UUID: //')
+echo $NEWSVNUUID
+
+echo -n "Updating SVN Remote config (old value: $(git config svn-remote.svn.url))... "
+git config svn-remote.svn.url $NEWSVNURL
+echo "done"
+
+echo -n "Updating Internal SVN metadata... "
+sed -i "s,reposRoot = .*$,reposRoot = $NEWSVNURL,;s,uuid = .*$,uuid = $NEWSVNUUID," .git/svn/.metadata
+echo "done"
+
+
+echo
+echo "OK now the fun stuff beings. You need to find the git commit at which you want to"
+echo "start the magiea import. This will typically require some investigation but the"
+echo "date will be around February 2011."
+echo "I will drop you to a shell. When you are done, simply copy the SHA1 sum and exit."
+echo "The commands you like want are 'git log trunk' and 'git show SHA1'"
+echo
+echo "Press any key to contiue."
+read -n 1
+bash
+echo
+echo "OK you're back :)"
+echo "What was the SHA1?"
+read resetsha1
+if [ -z "$resetsha1" ]; then
+  echo "You did not give any SHA1 sum. I will not reset the git repository and carry on importing"
+  echo "from it's current state. You can quit this script and start again if this is incorrect."
+else
+  echo "I got SHA1 '$resetsha1'. I hope that's correct".
+  echo
+  echo "I will now reset your git trunk and master branches. Is this OK? (press ctrl+c if not)"
+  read -n 1
+  git update-ref -m "Rewind SVN Git to pre-Magiea import" refs/remotes/trunk $resetsha1
+  git checkout master
+  git reset --hard trunk
+fi
+
+
+echo
+echo "I will now run 'svn log' on the software. You should be able to guess the right revision"
+echo "to base the import on. When done, simply copy (or remember) the revision number and enter it"
+echo "into this script."
+echo
+echo "Press any key to contiue."
+read -n 1
+
+svn log $NEWSVNURL/$SOFTWARE | less
+
+echo
+echo "OK you're back :)"
+echo "What was the revision number?"
+read revision
+revision=$(( $revision + 0 ))
+echo "I got revision '$revision'. I hope that's correct".
+echo
+echo "The next step is the dangerous bit. We will clear out all files in the current"
+echo "working copy, run an svn export and then drop you to a shell to investigate the differences"
+echo "In that shell you must git add any new files that appear and ensure you are happy with"
+echo "the generate state of things."
+echo
+echo "Continue? (press ctrl+c if not)"
+read -n 1
+git reset --hard trunk
+resetsha1=$(git rev-list --max-count=1 HEAD)
+# The below is a "safer" verion of rm -rf * that also deletes hidden files
+find . -depth -not -iwholename '.' -not -iwholename "./.git" -not -iwholename "./.git/*" -not -iwholename "./.git/.*" -delete
+svn export --force --ignore-keywords --ignore-externals -r $revision $NEWSVNURL/$SOFTWARE/trunk .
+echo
+echo "Dropping you to a shell. Use 'git status', 'git diff' and 'git add'."
+echo "DO NOT run 'git commit', I'll do that later for you."
+bash
+
+echo
+echo "OK you're back :)"
+echo "If everything is OK, and you're ready to continue, then hit return."
+read -n 1
+
+COMMITTXT=$(mktemp /tmp/commitmsg.XXXXXX)
+cat >$COMMITTXT <<EOF
+Synthesized commit during git-svn import combining previous Mandriva history with Magiea.
+
+This commit consitsts of the following subversion commits:
+
+EOF
+svn log -r 1:$revision $NEWSVNURL/$SOFTWARE >>$COMMITTXT
+
+COMMITDATE=$(svn log -r $revision $NEWSVNURL/$SOFTWARE | head -n2 | tail -n1| cut -d'|' -f3 | cut -d'(' -f1 | trim)
+git commit --author="Mageia SVN-Git Migration <svn-git-migration@mageia.org>" --date="$COMMITDATE" --file=$COMMITTXT -a
+rm -f $COMMITTXT
+
+echo
+echo "OK, looks like we're good to go :)"
+echo "Press any key to continue with the subversion import process".
+read -n 1
+
+git svn gc
+sha1=$(git rev-list --max-count=1 HEAD)
+echo
+echo -n "Updating trunk branch to include synthesised commit $sha1... "
+git update-ref -m "Reset to synthesized commit representing Magiea cleaned import (SVN Git)" refs/remotes/trunk $sha1
+echo "done"
+
+echo -n "Faking git-svn metadata to allow continuation... "
+printf "0000000: %08x%s\t................" $revision $sha1 | xxd -r -c24 >.git/svn/refs/remotes/trunk/.rev_map.$NEWSVNUUID
+echo "done"
+
+# Keep a small log of the sha1's etc.
+if [ ! -f ../svn-import.log ]; then
+  echo "software,startingcommit,startingrevision,fakecommit" >../svn-import.log
+fi
+echo "drakx,$resetsha1,$revision,$sha1" >>../svn-import.log
+
+echo "Continuing svn fetch"
+git svn fetch -A ../authors-transform.txt -r $(( $revision + 1 )):HEAD
+git reset --hard trunk
+echo
+echo "done"
+
+echo
+echo "Now creating bare git repository"
+git init --bare ../$SOFTWARE.git
+git remote rm origin
+git remote add origin ../$SOFTWARE.git
+git push --set-upstream master
+git push origin 'refs/remotes/*:refs/heads/*'
+
+pushd ../$SOFTWARE.git
+git branch -D trunk
+git branch -D origin/master
+git for-each-ref --format='%(refname)' refs/heads/tags | cut -d / -f 4 | \
+  while read ref; do
+    git tag "$ref" "refs/heads/tags/$ref"
+    git branch -D "tags/$ref"
+  done
+
+git gc --aggressive
+popd