mecu-graph.js: calculating the distance of two same curves results in a crash of the site

[KlausNie]

Originally posted by @KlausNie in https://github.com/sacdallago/mecu/issues/10#issuecomment-422309122

function findXNeighbours(v, scanline) {
    var f = function (forward, reverse) {
        var it = scanline.findIter(v);
        var u;
        while ((u = it[forward]()) !== null) {
            var uovervX = u.r.overlapX(v.r);
            if (uovervX <= 0 || uovervX <= u.r.overlapY(v.r)) {
                v[forward].insert(u);
                u[reverse].insert(v);
            }
            if (uovervX <= 0) {
                break;
            }
        }
    };
    f("next", "prev");
    f("prev", "next");
}

Uncaught TypeError: Cannot read property 'next' of null
    at f (mecu-graph.js:4059)
    at Object.findXNeighbours [as findNeighbours] (mecu-graph.js:4070)

seems to be happening when there are multiple proteins with the same read data. The points are then drawn all on the same position.

If there are too many proteins with the same read data (I found 5 - 7) the site goes into a freeze, the browser (chrome) halts the calculation and you are stuck with a ~4gb ram allocation. If the browser does not stop the calculation, the browser itself crashes and/or you run out of ram memory.

[sacdallago]

Seems dependent on https://github.com/tgdwyer/WebCola/issues/74

[sacdallago]

Solved?