bzr-cherry-pick

## 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]"
   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

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

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"

bzr merge --no-remember -r $((rev-1))..$rev $branch $cmdline_args
merged=$?

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