From db906a16671e7a0bf4703fbe819f2c4537da2c19 Mon Sep 17 00:00:00 2001
From: Dirk Eddelbuettel <edd@debian.org>
Date: Sun, 4 Dec 2016 21:17:46 -0600
Subject: [PATCH] contributed helper script (closes #34)

---
 ChangeLog                   |   5 ++
 local/scripts/git-remove.sh | 105 ++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100755 local/scripts/git-remove.sh

diff --git a/ChangeLog b/ChangeLog
index 471536930..54c21e603 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-12-04  Dirk Eddelbuettel  <edd@debian.org>
+
+	* local/scripts/git-remove.sh: Script contributed in GitHub Issue #34
+	to reduce disk footprint of the archive
+
 2016-11-18  Dirk Eddelbuettel  <edd@debian.org>
 
 	* DESCRIPTION: Release 1.62.0-1
diff --git a/local/scripts/git-remove.sh b/local/scripts/git-remove.sh
new file mode 100755
index 000000000..3121baf38
--- /dev/null
+++ b/local/scripts/git-remove.sh
@@ -0,0 +1,105 @@
+#!/bin/bash
+# Remove and purge old mistakes and/or unwanted big files from git history
+# author: Iñaki Ucar <i.ucar86@gmail.com>
+# based on: http://blog.ostermiller.org/git-remove-from-history
+
+if [ "$#" -ne 2 ]; then
+  echo "usage: $0 <repo-URL> <pattern>"
+  exit 1
+fi
+
+URL=$1
+EXT=$2
+
+confirm () {
+  read -r -p "${1:-Are you sure? [y/N]} " response
+  case $response in
+    [yY][eE][sS]|[yY])
+      true
+      ;;
+    *)
+      false
+      ;;
+  esac
+}
+
+clean () { rm -rf /tmp/workingrepo; }
+
+# Create a clone of the repository
+cd /tmp
+git clone $URL workingrepo
+if [ "$?" -ne 0 ]; then
+  echo ""
+  echo "ooops! something went wrong cloning the repo!"
+  clean
+  exit 2
+fi
+cd workingrepo
+for branch in `git branch -a | grep remotes | grep -v HEAD | grep -v master`; do
+    git branch --track ${branch##*/} $branch
+done
+
+# Find the files you want to remove
+FILE_LIST=$(git rev-list master | \
+  while read rev; do
+    git ls-tree -lr $rev | cut -c54- | sed -r 's/^ +//g;'
+  done | sort -u | perl -e 'while (<>) {
+    chomp; @stuff=split("\t");$sums{$stuff[1]} += $stuff[0];
+  } print "$sums{$_} $_\n" for (keys %sums);' | \
+  sort -rn | grep $EXT)
+echo ""
+echo "You're going to remove the following files:"
+echo ""
+echo "$FILE_LIST"
+echo ""
+! confirm && clean && exit 0
+FILE_LIST=$(echo "$FILE_LIST" | cut -d" " -f2)
+echo ""
+
+# Rewrite history and remove the old files
+git filter-branch --tag-name-filter cat --index-filter \
+  "git rm -r --cached --ignore-unmatch ${FILE_LIST//$'\n'/ }" \
+  --prune-empty -f -- --all
+
+# Prune all references with garbage collection and reclaim space
+rm -rf .git/refs/original/
+git reflog expire --expire=now --all
+git gc --aggressive --prune=now
+
+# Verify they have been removed
+FILE_N=$(git rev-list master | \
+  while read rev; do
+    git ls-tree -lr $rev | cut -c54- | sed -r 's/^ +//g;'
+  done | sort -u | perl -e 'while (<>) {
+    chomp; @stuff=split("\t");$sums{$stuff[1]} += $stuff[0];
+  } print "$sums{$_} $_\n" for (keys %sums);' | \
+  sort -rn | grep $EXT | wc -l)
+if [ "$FILE_N" -ne 0 ]; then
+  echo ""
+  echo "ooops! something went wrong removing the files!"
+  clean
+  exit 3
+fi
+
+# Push the history changes
+echo ""
+echo "Files successfully removed! Let's push the changes..."
+echo ""
+! confirm && exit 0
+echo ""
+git push origin --force --all
+git push origin --force --tags
+clean
+
+# Done
+echo ""
+echo "Done! Now, you should tell your collaborators to rebase and prune their local copies with"
+echo ""
+echo "  cd MY_LOCAL_GIT_REPO"
+echo "  git fetch origin"
+echo "  git rebase"
+echo "  git reflog expire --expire=now --all"
+echo "  git gc --aggressive --prune=now"
+echo ""
+echo "or to clone a fresh copy. And don't push that again! ;-)"
+echo ""