[9.0a] Compare tool syncs wrong lines

[MVV]

Well, it may be not easy to meet the conditions but I face it pretty often...

1. Please compare these two text files aaa.txt and bbb.txt in compare tool (in this order) with enabled "Ignore repeated spaces" and disabled "Ignore frequent lines" options:

Code: Select all

function get_gettimeofday() {
    return gettimeofday();
}



class MyClass {
    // some comment
    // some other comment
    var $files = array();
    var $var1;
    var $var2;


    //TODO go sleep
    function process($filename){
        do_something(FALSE, $filename);
        return result($filename);
    }

usage() {
    echo "usage: $0 COMMAND"
    echo
    echo "Manage php source tarball lifecycle."
    echo
    echo "Commands:"
    echo "   extract  extract php source tarball into directory $dir if not already done."
    echo "   delete   delete extracted php source located into $dir if not already done."
    echo
}

case "$1" in
extract)
    mkdir -p "$dir"
    if [ ! -f "$dir/.docker-extracted" ]; then
        tar -Jxf /usr/src/php.tar.xz -C "$dir" --strip-components=1
        touch "$dir/.docker-extracted"
    fi
    ;;

delete)
    rm -rf "$dir"
    ;;

*)
    usage
    exit 1
    ;;
esac

Code: Select all

function get_gettimeofday() {
    return gettimeofday();
}

function get_true() {
    return FALSE;
}

if (!function_exists('test_function')) {
    function test_function($s) {
        // yohoh
        // gfhggggg
        //dfgdfgdfgdfg
    }
}



class MyClass {
    // some comment
    // some other comment
    var $files = array();
    var $var1;
    var $var2;

    // ini="/usr/local/etc/php/conf.d/${iniName:-"docker-php-ext-$ext.ini"}"


    //TODO go sleep
    function process($filename){
        do_something(FALSE, $filename);
        return result($filename);
    }

usage() {
    echo "usage: $0 COMMAND"
    echo
    echo "Manage php source tarball lifecycle."
    echo
    echo "Commands:"
    echo "   extract  extract php source tarball into directory $dir if not already done."
    echo "   delete   delete extracted php source located into $dir if not already done."
    echo
}

case "$1" in
extract)
    mkdir -p "$dir"
    if [ ! -f "$dir/.docker-extracted" ]; then
        tar -Jxf /usr/src/php.tar.xz -C "$dir" --strip-components=1
        touch "$dir/.docker-extracted"
    fi
    ;;

delete)
    rm -rf "$dir"
    ;;

*)
    usage
    exit 1
    ;;
esac

Note that comparer has synced wrong lines at some moment and all other lines are synced incorrectly (though they are 100% equal).

2. Simply swap panels (from context menu) and press Compare button! Now comparer have synced proper lines!

3. Swap panels back and press Compare button to get bad sync again, and enable "Ignore frequent lines" option or disable "Ignore repeated spaces" option to set them into same state (enabled or disabled) and press Compare again. Comparer have synced proper lines again!


So it is quite strange why TC syncs these files (which provide only a sample of real situation of course) in first case.

[petermad]

I can confirm the described behavior - it is not a new thing - TC 8.52a behaves the same way.

[ghisler(Author)]

The tool goes from line to line in the left file, and looks for matching lines in the right. Since there is no "correct" way to do this, this may lead to different results. That's why there is the function "Resync from here", so you can match the lines to gether where YOU think they belong together.

The problem here are the lines with a single "}" in them. TC finds them as a match, and therefore misses the match of longer lines.