svn-cip

#!/bin/bash
# svn-cip, an svn equivalent for git add --patch
# Usage:
#  svn-cip <file> [<file> [...]]
function usage(){
    sed 's/^........//' <<USAGE
        Usage: $(basename "$0") [--changelist <ARG>] [file [file...]]
        Options:
            --cl,--changelist <ARG>
                Use the specified SVN changelist in addition to any specified files

            --
                Treat all further arguments as filenames

            --help
                Display this message and exit
USAGE
}

function fully_qualify(){
    local file="$1"
    readlink -fn "$([ "${file#-}" = "$file" ]||echo -n './')$file"
}

if [ "$1" = "help" ]; then
    if [ $# -gt 1 ]; then
        echo "Subcommand 'help' doesn't accept option '$2'" >&2
        echo "Type '$(basename "$0") help' for usage." >&2
        exit 1
    fi
    usage
    exit 0
fi

no_args=0
changelists=()
files=()
while [ $# -gt 0 ]; do
    if [ "$no_args" = "1" ]; then
        files[${#files[@]}]="$(fully_qualify "$1")"
        shift
        continue
    fi

    case "$1" in
        --cl|--changelist)
                shift
                changelist="$1"
                if [ -z "$changelist" ]; then
                    echo "Invalid changelist name '$changelist'" >&2
                    exit 1
                fi
                changelists[${#changelists[@]}]="$changelist"
            ;;
        --cl=|--changelist=)
                changelist="$(sed '1s/^[^=]*=//')"
                if [ -z "$changelist" ]; then
                    echo "Invalid changelist name '$changelist'" >&2
                    exit 1
                fi
                changelists[${#changelists[@]}]="$changelist"
            ;;
        --help)
                usage
                exit 0
            ;;
        --)
            no_args=1
            ;;
        -*)
            echo "Unknown argument: $1" >&2
            exit 1
            ;;
        *)
            files[${#files[@]}]="$(fully_qualify "$1")"
            ;;
    esac
    shift
done

# look through all files and determine topmost directory
function longest_common_prefix(){
	perl /dev/fd/3 "$1" 3<<-'PERL'
		#!/usr/bin/perl
		use strict;
		my $delim = $ARGV[0];

		my $common = undef;
		binmode STDIN;
		$/ = "\0";
		STRING: while(<STDIN>){ chomp;
			my @parts = split( $delim );
			my $string = '';
			my @candidate_prefixes = ($delim);
			foreach my $part (@parts) {
				if( $part eq "" ){ next; }
				$string = $string . $delim . $part;
				push @candidate_prefixes, $string;
			}
			foreach my $candidate_prefix (reverse @candidate_prefixes){
				if(
					!defined($common) ||
					$candidate_prefix eq $delim ||
					$candidate_prefix eq $common ||
					(
						length($candidate_prefix.$delim) <= length($common) &&
						substr($common, 0, length($candidate_prefix)+1) eq $candidate_prefix.$delim
					)
				){
					$common = $candidate_prefix;
					next STRING;
				}
			}
		}
		if( !defined($common) ){
			exit(1);
		}
		print $common;
		exit(0);
	PERL
}

if [ ${#files[@]} -eq 0 -o ${#changelists[@]} -gt 0 ]; then
    parent="$(fully_qualify .)"
    [ -d "$parent/.svn" ] || {
        echo "Not an SVN directory." >&2
        exit 1
    }

    changelist_args=()
    for changelist in "${changelists[@]}"; do
        changelist_args[${#changelist_args[@]}]="--cl"
        changelist_args[${#changelist_args[@]}]="$changelist"
    done

    while [ -d "$parent/.svn" ]; do
        top="$parent"
        parent="$(dirname "$parent")"
    done
    cd "$top"
    oldIFS="$IFS"
    IFS=$'\n'
    echo -n "Generating changelist from 'svn st' output..." >&2
    status_files=( $(svn st "${changelist_args[@]}" | sed -n 's/^M.......//p') ) || exit 1
    IFS="$oldIFS"
    for file in "${status_files[@]}"; do
        files[${#files[@]}]="$(fully_qualify "$file")"
    done
    echo " done." >&2
fi

for file in "${files[@]}"; do
    if [ -d "$file" ]; then
        [ -d "$file/.svn" ] || {
            echo "'$file' is not a working copy" >&2
            exit 1
        }
    else
        [ -d "$(dirname "$file")/.svn" ] || {
            echo "'$file' is not controlled by svn" >&2
            exit 1
        }
    fi
done

for file in "${files[@]}"; do
    files[${#files[@]}]="$(fully_qualify "$file")"
done

common="$(for file in "${files[@]}"; do
	echo -n "$file"
	echo -en '\0'
done | longest_common_prefix /)"
common="$(
    parent="$(dirname "$common")"
    while [ -d "$parent/.svn" ]; do
        common="$parent"
        parent="$(dirname "$common")"
    done
    echo "$common"
)"

[ -d $common ] || common="$(dirname "$common")"

GIT_DIR="$(mktemp -d --tmpdir "svn-cip$([ "$common" = "/" ] || echo ".$(basename "$common")" ).XXXXXXXXXX")" || exit 1
function _cleanup(){
	rm -rf "$GIT_DIR"
}
trap _cleanup EXIT SIGHUP SIGINT SIGQUIT SIGTERM || exit 1

GIT_WORK_TREE="$common"
export GIT_DIR
export GIT_WORK_TREE
git init --quiet || exit 1

function filepaths(){
    local file
    local prefix
    for file in "$@"; do
        file="$(fully_qualify "$file")"
        if [ "$common" = "/" ]; then
            file="${file:1}"
        else
            prefix="$common/"
            file="${file:${#prefix}}"
        fi
        echo -n "$file"
        echo -en '\0'
    done | sort -rz
}

function hash_svn_base(){
    local filepath="$1"
    svn cat -rBASE "$filepath" | git hash-object -t blob -w --stdin
}

function hash_file(){
    local filepath="$1"
    cat "$filepath" | git hash-object -t blob -w --stdin
}

function update_index(){
    local callback="$1"
    local file="$2"

    hash="$("$callback" "$common/$file")"
    git update-index --add --cacheinfo '100644' "$hash" "$file" || exit 1
}

function commit(){
    local tree="$1"
    local parent="$2"
    local message="$3"
    local date="$(date +'%s %z')"

    [ -n "$parent" ] && parent="$(echo; echo "parent $parent")"

    {
        sed 's/^\s*//' <<COMMIT
            tree $tree$parent
            author nobody <nobody@nowhere> $date
            committer nobody <nobody@nowhere> $date

            $message
COMMIT
    } | git hash-object -t commit -w --stdin
}

filepaths "${files[@]}" | while read -d $'\0' file; do
    update_index hash_svn_base "$file" || exit 1
done &&
git reset -q "$(commit "$(git write-tree)" '' 'BASE')" &&
git tag base &&
git add --patch &&
git reset -q "$(commit "$(git write-tree)" "$(git rev-parse refs/tags/base)" 'PARTIAL')" &&
git tag partial &&
filepaths "${files[@]}" | while read -d $'\0' file; do
    update_index hash_file "$file" || exit 1
done &&
git reset -q "$(commit "$(git write-tree)" "$(git rev-parse refs/tags/base)" 'FULL')" &&
git tag full || exit 1

if git diff --quiet refs/tags/base refs/tags/partial; then
    echo "No changes to commit." >&2
    exit 1
fi

#confirm with user that this is ok, eg: output diffs which will actually be sent
while true; do
    read -p 'Are you sure you wish to continue [y,n,a,r,q,e,?]? ' response
    case "$response" in
        y|ye|yes)
            if git diff --quiet refs/tags/base refs/tags/partial; then
                echo "No changes to commit." >&2
                exit 1
            fi
            break
            ;;
        n|no|q|qu|qui|quit)
            exit 0
            ;;
        e|ex|exa|exam|exami|examin|examine)
            if git diff --quiet refs/tags/base refs/tags/partial; then
                echo "No changes to commit."
            else
                git diff refs/tags/base refs/tags/partial
            fi
            continue
            ;;
        r|re|rem|remo|remov|remove)
            git reset -q refs/tags/partial &&
            git reset -q --soft refs/tags/base &&
            git reset --patch &&
            git reset -q "$(commit "$(git write-tree)" "$(git rev-parse refs/tags/base)" 'PARTIAL')" &&
            git update-ref refs/tags/partial HEAD || exit 1
            continue
            ;;
        a|ad|add)
            git reset -q refs/tags/partial &&
            git reset -q --soft refs/tags/base &&
            git add --patch &&
            git reset -q "$(commit "$(git write-tree)" "$(git rev-parse refs/tags/base)" 'PARTIAL')" &&
            git update-ref refs/tags/partial HEAD || exit 1
            continue
            ;;
        *)
            sed 's/^\s*//' <<HELP
                y - yes, commit changes to svn
                n - no, exit
                a - add more changes to the commit
                r - remove changes from the commit
                q - quit (same as "no")
                e - examine changes to be committed
                ? - print help
HELP
    esac
done

function _restore(){
    git reset -q --hard refs/tags/full &&
    _cleanup
}
trap _restore EXIT SIGHUP SIGINT SIGQUIT SIGTERM || exit 1

git reset -q --hard refs/tags/partial || exit 1
svn commit "${files[@]}" || exit 1
exit 0