make_polyglot.sh

#!/usr/bin/env bash

if [ "$#" -ne 2 ]; then
    (>&2 echo -e "Usage: $0 SOURCE_PDF OUTPUT_PDF\n")
    exit 1
fi

# Make sure that the git username and E-mail variables are set,
# else some of the commands below will fail:
if [[ -z `git config --list | grep user.email | sed 's/^[^=]*=//'` ]]; then
    (>&2 echo -e "\nYou do not have the git user.email variable set!\nPlease run \`git config --global user.email \"your@email.com\"\`\n")
    exit 2
fi
if [[ -z `git config --list | grep user.name | sed 's/^[^=]*=//'` ]]; then
    (>&2 echo -e "\nYou do not have the git user.name variable set!\nPlease run \`git config --global user.name \"Your Name\"\`\n")
    exit 3
fi

SOURCE=$1
OUTPUT=$2

if [ `wc -c <$SOURCE` -gt 65535 ]; then
    (>&2 echo "Warning: $SOURCE is greater than 0xFFFF bytes. This might not work!")
fi

BRANCH_NAME=PolyglotBranch

git ls-files $OUTPUT --error-unmatch 1>/dev/null 2>&1
if [ $? -ne 1 ]; then
    (>&2 echo -e "Error: The output file $OUTPUT is already tracked by git!\n       This will not work! Please choose another output file.\n       This might happen if you just cloned this repo from a PDF polyglot.\n       If so, simply run \`git checkout master && git branch -d $BRANCH_NAME\`\n")
    exit 4
fi

git rev-parse --verify $BRANCH_NAME 1>/dev/null 2>&1
if [ $? -eq 0 ]; then
    (>&2 echo -e "Error: A branch named $BRANCH_NAME already exists!\n       You need to either delete this branch\n       or set a different value for the BRANCH_NAME variable\n       in $0\n")
    exit 5
fi

CURRENT_BRANCH=`git rev-parse --abbrev-ref HEAD`

cp $SOURCE $OUTPUT

rm -f ${OUTPUT}.log

git stash save MAKINGPOLYGLOT 1>>${OUTPUT}.log 2>&1
git stash list | grep -q MAKINGPOLYGLOT
HAS_STASH=$?

if [ $HAS_STASH -eq 0 ]; then
    echo "There are local changes! Saving them to a stash so they are not lost..."
fi

echo "Creating temporary branch ${BRANCH_NAME}..."
git checkout -b $BRANCH_NAME 1>>${OUTPUT}.log 2>&1
if [ $HAS_STASH -eq 0 ]; then
    echo "Applying the stash to the new branch..."
    git stash apply 1>>${OUTPUT}.log 2>&1
fi
echo "Making the polyglot..."
git update-index --add --cacheinfo 100644 `git hash-object -w $OUTPUT` $OUTPUT 1>>${OUTPUT}.log 2>&1
TREE_HASH=`git write-tree`
echo 'Polyglot PDF' | git commit-tree $TREE_HASH 1>>${OUTPUT}.log 2>&1
git commit -a -m 'Creating the Polyglot' 1>>${OUTPUT}.log 2>&1
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
PATH=$DIR/git:$PATH git bundle create ${OUTPUT}.bundle --do-not-compress `git hash-object $OUTPUT` --all 1>>${OUTPUT}.log 2>&1
echo "Switching back to branch ${CURRENT_BRANCH}..."
git checkout $CURRENT_BRANCH 1>>${OUTPUT}.log 2>&1
echo "Deleting ${OUTPUT} from being staged..."
echo "It is normal for the following command to produce an error:" >> ${OUTPUT}.log
git rm --cached -f ${OUTPUT} 1>>${OUTPUT}.log 2>&1
echo "Deleting temporary branch ${BRANCH_NAME}..."
git branch -D $BRANCH_NAME 1>>${OUTPUT}.log 2>&1
mv ${OUTPUT}.bundle $OUTPUT

if [ $HAS_STASH -eq 0 ]; then
    echo "Re-applying the stash to restore local changes..."
    git stash pop 1>>${OUTPUT}.log 2>&1
fi

echo "Created $OUTPUT"