A tool for cherry-picking revisions from bazaar repositories

bzr-cherry-pick

#!/bin/bash
#
# Simply cherry picks a revision from a bazaar branch, cloning its metadata
#
# Usage:
#  bzr-cherry-pick lp:unity 1234

if ! (bzr root &> /dev/null); then
  echo "It seems you're not in a bazaar branch directory"
  exit 1
fi

if [ -z "$1" ]; then
   echo "$(basename $0) <branch location> <revision number> [--debchange] [--no-commit] [--use-merge]"
   exit 1
fi

if ! [[ $2 =~ ^-?[0-9]+$ ]]; then
   echo "You need to provide the revision number you want to pick"
   exit 1
fi

if [ "$(bzr diff | head -n1 | wc -l)" -gt 0 ]; then
  echo "Impossible to work in a branch which has uncommitted changes"
  exit 1
fi

branch=$1
shift
rev=$1
shift
cmdline_args=$*

use_debchange=false
no_commit=false
use_merge=false

if (echo "$cmdline_args" | grep -q -w -- "--debchange"); then
  cmdline_args="${cmdline_args//--debchange/}"
  if [ -f debian/changelog ]; then
    use_debchange=true
  fi
fi

if (echo "$cmdline_args" | grep -q -w -- "--no-commit"); then
  cmdline_args="${cmdline_args//--no-commit/}"
  no_commit=true
fi

if (echo "$cmdline_args" | grep -q -w -- "--use-merge"); then
  cmdline_args="${cmdline_args//--use-merge/}"
  use_merge=true
fi

export LC_ALL=C.UTF-8

log="$(bzr log -n1 -r $rev $branch $cmdline_args)"
log_msg="$(echo "$log" | sed '0,/^message:$/d' | tail -n +1 | sed -e 's/^\s*//' | sed '/^Approved by: /d')"
log_author="$(echo "$log" | sed -n 's/^author: //p')"
log_time="$(echo "$log" | sed -n 's/^timestamp: \([A-Za-z]\+ \)\?//p')"
log_bugs="$(echo "$log" | sed -n 's/^fixes bugs\?: //p' | sed 's,https://launchpad.net/bugs/,,g')"

if [ -z "$log_author" ]; then
  log_author="$(echo "$log" | sed -n 's/^committer: //p')"
fi

if [ -z "$log_author" ]; then log_author="$(bzr whoami)"; fi
if [ -z "$log_bugs" ]; then log_bugs="$(echo "$log_msg" | sed '/Fixes: #[0-9]\+/!d' | sed 's/.*Fixes: #\([0-9#, ]\+\).*/\1/m' | sed 's/[,#]//g')"; fi
if [ -z "$log_bugs" ]; then log_bugs="$(echo "$log_msg" | sed '/(LP: [^)]\+)/!d' | sed 's/.*(LP: \([^)]\+\)).*/\1/m' | sed 's/[,#]//g')"; fi
log_msg=$(echo "$log_msg" | sed 's/Fixes: #[0-9, #]\+//')
log_msg=$(echo "$log_msg" | sed 's/(LP: [^)]\+)//')

if [ "$log_author" == "Bileto Bot <ci-train-bot@canonical.com>" ]; then
  echo "Ignoring release commit..."
  exit 0
fi

echo "Author: $log_author"
echo "Time: $log_time"
for bug in $log_bugs; do echo "Bug: https://launchpad.net/bugs/$bug"; done;
echo -e "Message:\n$log_msg\n"

if [ "$use_merge" == true ]; then
  bzr merge --no-remember -c $rev $branch $cmdline_args
  merged=$?
else
  bzr di -c $rev $branch $cmdline_args | patch -p0
  merged=$?

  for i in $(bzr di -c $rev $branch $cmdline_args | lsdiff); do
    bzr add $i
  done
fi

if [ "$merged" == 0 ] && [ "$(bzr di | head -n1 | wc -l)" == 0 ]; then
  echo "Revision $rev has no changes to merge, ignoring it..."
  exit 0
fi

# msg_file=$(mktemp /tmp/bzr-cherry-pick.XXXXXXX)
# echo "$log_msg" > $msg_file

args="--message=\"${log_msg//\"/\\\"}\" --author=\"${log_author//\"/\\\"}\" --commit-time=\"$log_time\""
for bug in $log_bugs; do args="$args --fixes=\"lp:$bug\""; done;

if [ $use_debchange == true ]; then
  change="$(echo "$log_msg" | head -n1)"
  if [ -n "$log_bugs" ]; then
    read -r -a bugs_array <<< "$log_bugs"
    change="$change ($(printf "LP: #%s, " "${bugs_array[@]}")"
    change=${change%, }")"
  fi

  unset DEBFULLNAME DEBEMAIL NAME EMAIL
  export DEBFULLNAME="$(echo "$log_author" | sed "s/\([^<]*\)<\([^>]\+\)>/\1/g" | sed -e 's/  *$//')"
  export DEBEMAIL="$(echo "$log_author" | sed "s/[^<]*<\([^>]\+\)>/\1/g" | sed -e 's/  *$//')"
  debchange --multimaint-merge --release-heuristic changelog -- $change
fi

if [ $no_commit == true ]; then
  echo -e "No committing, you can do this manually by using\n  bzr commit $args"
  exit $merged
fi

if [ $merged == 0 ]; then
  if [ "$(bzr di | head -n1 | wc -l)" -gt 0 ]; then
    #echo bzr commit "$args"
    eval "$(echo bzr commit "$args")"
  fi
else
  if [ "$(bzr conflicts -q | head -n1 | wc -l)" -gt 0 ]; then
    echo -e "\nMerging of version $rev failed, impossible to commit. Please use 'bzr resolve' to fix the issues and then commit with\n  bzr commit $args"
    exit 1
  fi
fi

# rm -f $msg_file

Minor suggestion: If you add --no-remember to the bzr merge command it will not add a submit_branch to branch.conf.
This for example makes Bazaar Explorer raise a red flag because the "Branch has changes not present in its submit branch." and makes it do additional (unnecessary) work...

Thanks for this really handy script! It made bzr bearable for me 😉

Thanks @Ede123, I've added it