Uncaught TypeError: Cannot read property 'length' of null (CollisionTile in Tile.reloadSymbolData)

[sguignot]

mapbox-gl-js version: 0.28
Not reproduced with 0.26 ; Maybe present in 0.27 too.

Steps to Trigger The Error

1. Setup a geojson layer with a lot of features: for example, every building polygons from OSM in a city like Paris, France.
2. Zoom in and out randomly inside the city
3. Sometimes the following error occurs (details and stack below): Uncaught TypeError: Cannot read property 'length' of null

Error

Uncaught TypeError: Cannot read property 'length' of null
    at new CollisionTile
    at Tile.reloadSymbolData
    at Tile.done
    at Actor.receive

var CollisionTile = function CollisionTile(angle, pitch, collisionBoxArray) {
    if (typeof angle === 'object') {
        var serialized = angle;
        collisionBoxArray = pitch;
        angle = serialized.angle;
        pitch = serialized.pitch;
        this.grid = new Grid(serialized.grid);
        this.ignoredGrid = new Grid(serialized.ignoredGrid);
    } else {
        this.grid = new Grid(EXTENT, 12, 6);
        this.ignoredGrid = new Grid(EXTENT, 12, 0);
    }

    this.minScale = 0.5;
    this.maxScale = 2;

    this.angle = angle;
    this.pitch = pitch;

    var sin = Math.sin(angle),
        cos = Math.cos(angle);
    this.rotationMatrix = [cos, -sin, sin, cos];
    this.reverseRotationMatrix = [cos, sin, -sin, cos];

    // Stretch boxes in y direction to account for the map tilt.
    this.yStretch = 1 / Math.cos(pitch / 180 * Math.PI);

    // The amount the map is squished depends on the y position.
    // Sort of account for this by making all boxes a bit bigger.
    this.yStretch = Math.pow(this.yStretch, 1.3);

    this.collisionBoxArray = collisionBoxArray;
    if (collisionBoxArray.length === 0) { // <===== !!!! CRASH HERE !!!!
        // the first collisionBoxArray is passed to a CollisionTile

[mollymerp]

@sguignot thanks for reporting this issue! could you please provide a jsfiddle / jsbin that reproduces this error?

it is possible that #3681 fixes this exception, so I'd like to verify before investigating further.

thanks!

[lbud]

👍 after some investigation, I suspect this is a different issue from #3681, but we haven't been able to reproduce it so far 😬 a jsfiddle doing so would be very helpful!

[lucaswoj]

Closing pending reproduction steps

[sguignot]

mapbox-gl-js versions: 0.27, 0.28, 0.29, 0.30
Not reproduced with 0.26, this bug is present in all versions since 0.27.

Steps to Trigger The Error

1. Get a mouse device that supports scrolling with high speed / velocity / inertia (I am using a Magic mouse 2 from Apple: http://www.apple.com/shop/product/MLA02LL/A/magic-mouse-2).
2. Go to the following blog demo: https://www.mapbox.com/bites/00304/
3. Open the browser console and add "length" as error filter to avoid the flood of 404 errors.
4. Quickly move the camera where features are located: zoom in and out quickly, pan and change the camera pitch. In less than a minute of zooming and moving the camera I reproduce the following error in the console: Uncaught TypeError: Cannot read property 'length' of null (browsers on which I reproduce this error: Google Chrome 55 and Safari 10).

Error

Uncaught TypeError: Cannot read property 'length' of null
    at new CollisionTile
    at Tile.reloadSymbolData
    at Tile.done
    at Actor.receive

Please re-open, this issue is blocker for us (it occurs more often than in your demo).

[musicformellons]

I am getting these as well (version 0.30.0):

Uncaught TypeError: Cannot read property 'length' of null
    at new CollisionTile (eval at <anonymous> (0.50f3799….js:263), <anonymous>:157:670)
    at Tile.reloadSymbolData (eval at <anonymous> (0.50f3799….js:263), <anonymous>:101:1495)
    at Tile.t (eval at <anonymous> (0.50f3799….js:263), <anonymous>:101:2104)
    at Actor.receive (eval at <anonymous> (0.50f3799….js:263), <anonymous>:213:738)
CollisionTile @ mapbox-gl.js?31ef:157
Tile.reloadSymbolData @ mapbox-gl.js?31ef:101
t @ mapbox-gl.js?31ef:101
Actor.receive @ mapbox-gl.js?31ef:213

And I am indeed using a geojson layer.

[mourner]

@sguignot can you please try reproducing this again and posting the properties of this (Tile instance) on the breakpoint where it happens (in either done or reloadSymbolData)? I'm specifically interested in the values of this.state and this.collisionBoxArray.

[sguignot]

@mourner sorry for the delay.
I ran the demo "Restaurants Complaints NYC" with https://api.tiles.mapbox.com/mapbox-gl-js/v0.30.0/mapbox-gl-dev.js
I put conditional breakpoint on line 49 of file collision_tile.js (condition is !collisionBoxArray)
line 49: if (collisionBoxArray.length === 0) {

When the error occurs (ie !collisionBoxArray), I have this.state : "reloading" and this. collisionBoxArray : null. You will find the detailed context for each frame of the call stack below:

[sguignot]

@mourner it seems a lot easier to reproduce this error when spinning the map using the right click, check out the following screencast:

[mourner]

@sguignot finally managed to reproduce, thanks a lot for the help! On it now.

[GuillaumeTS]

Reproduced with the same steps with mapbox 0.37 and 0.38.

[lbud]

I can also reproduce on master — will produce a minimal example.

[lbud]

https://jsbin.com/sujonoyupa/edit?html,output — error appears after clicking the button a few times.

[sguignot]

@lbud Thanks for the jsbin, do you have any news regarding the bugfix?

We have a lot of logs/alerts in production because of this regression, it would be great to have a fix in the next version (v0.39).

[edap]

I'm having the same problem in production

[mollymerp]

@sguignot @edap would you be willing to see if the error is still happening on master? I think it was fixed in caf4cfb as I can no longer reproduce on master.

[mollymerp]

Closing for now – please reopen if you continue to see this issue after the next release (this afternoon)

[brncsk]

This is still happening for me on 0.39.1.

[sguignot]

Thanks @mollymerp it's fixed on my side, I just tested with 0.39.1 and errors are gone.

For quick testing, you can reproduce the error in 0.38 here after a few clicks:
https://jsbin.com/sonuvoyofe/1/edit?html,output

Here in 0.39.1 you can check error is gone:
https://jsbin.com/hoyaputude/1/edit?html,output

I'm going to deploy 0.39.1 in production soon, then after a few days I will confirm if the error is completely gone or if it persists (there may be several root causes after all).

[EbilPanda]

yeah also happening to me occasional when zooming or using the fly-method...
I'm using custom tileset and style.

Error:

ERROR TypeError: Cannot read property 'length' of null
at new CollisionTile (mapbox-gl.js:337)
at Function.CollisionTile.deserialize (mapbox-gl.js:337)
at Tile.reloadSymbolData (mapbox-gl.js:215)
at mapbox-gl.js:215
at Actor.receive (mapbox-gl.js:397)
at t.invokeTask (polyfills.js:3)
at Object.onInvokeTask (core.es5.js:4140)
at t.invokeTask (polyfills.js:3)
at r.runTask (polyfills.js:3)
at Worker.invoke (polyfills.js:3)

using 0.39.1 via npm, with webpack 3.4.1 and excluded mapbox from uglifier (exports.module.noParse = /(mapbox-gl)\.js$/;) in an ionic2-app (angular4)

[mollymerp]

@EbilPanda @brncsk sorry you're still running into this – can you cut a new issue with a jsfiddle/jsbin that can reproduce the issue?

[EbilPanda]

i'm sorry I'm currently not able to reproduce the error on fiddl/bin :(
I think the problem is with webpack/uglify that stills running over the already uglified code and then occures error, I think I will go with the cdn to test if it happends there too

[EbilPanda]

But i found the error line in the mapbox-gl-devjs: Line 23052 if (collisionBoxArray.length === 0)
I've attached to scope-variables directly before the error occured (Line 23051).
mapbox.scope.json.txt

[shf123]

It also still happens for me in version 0.39.1.

I made an example in jsfiddle:
https://jsfiddle.net/stighef/y5z4cwLt/

A FeatureCollection with 10 000 rectangles are toggled on and off when
the zoomend-event is triggered.

After zooming out and in, I get lots of these:

[sguignot]

@mollymerp I reopen the issue because the jsfiddle from @shf123 triggers the error with version 0.39.1

[snkashis]

Yeah, still an issue for me in 0.39.1 as well.

[apolishch]

Yeah happening for me on 0.39.1 as well

[mourner]

Thanks a lot for the new test case — got it to immediately reproduce! Will make fixing much easier.

[mourner]

Hey everyone, we have a fix in #5185 — until we ship this in a release, feel free to use this patch for a custom build of GL JS if you experience this problem.