Uncaught Error: entity w7409928 not found

[tko]

Starting the editor seems to sometimes throw an exception leaving it in a state where not all details are loaded and seemingly never will. Reloading the page sometimes works, sometimes throws the same exception with different entity id (I've seen w7409928 and w59195767)

id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:57 Uncaught Error: entity w7409928 not found
    at hd.entity (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:57)
    at hd.parentWays (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:57)
    at t (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:4)
    at Object.Rd.i.rebase (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:4)
    at Object.merge (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:11)
    at n (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:11)
    at o (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:11)
    at id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:59
    at t (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:59)
    at l (id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:59)
entity @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:57
parentWays @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:57
t @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:4
Rd.i.rebase @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:4
merge @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:11
n @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:11
o @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:11
(anonymous) @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:59
t @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:59
l @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:59
i.onreadystatechange @ id-63ec25b478c2af431aa10a2e5a9b6d4416ec6423217d481dc9b6d9cc3ee0bc11.js:59

http://www.openstreetmap.org/edit?editor=id#map=18/52.33752/4.59592

Chrome 58.0.3029.41 beta (64-bit), OS X 10.11.6

[tyrasd]

I saw something very similar in Chrome 58.0.3029.54 (Official Build) beta (64-bit), V8 5.8.283.24 on Linux a few days ago:

Note the debug commands I issued after hitting the breakpoint – very strange!

As far as I can see it's probably a race condition inside Chrome's V8 doing some overly optimistic optimization or something. Not sure how to best follow up on this… Wait and see if this even lands in Chrome 58?

[bhousel]

Hmm @tyrasd yeah that makes no sense. It really does seem to be a V8 bug.

[oiva]

I'm seeing this too. Chrome 60.0.3107.4 (Official Build) dev (64-bit) and iD 2.2.1. Repeats on almost every load and as a result some of details are missing.

[oiva]

Not sure if this is related but bumped into an error in Firefox where entities were undefined in coreGraph rebase:

iD/modules/core/graph.js

Line 130 in b07bf8e

for (i = 0; i < entities.length; i++) {

I can make a separate issue of this if necessary.

Edit: created #4072

[tyrasd]

We see this now even in the latest stable Chrome build (59.0.3071.86 (Official Build) (64-bit) / V8 5.9.211.31) on Linux (on Windows it's fine apparently, see #4094 (comment)). 😒

[tyrasd]

This is soo strange. No idea why and what is happening. (It's also quite hard to search for this in Chrome's bug tracker.)

What I found is: If one adds if (!entity) entity = this.entities.__proto__[id]; after core/graph.js#L36, it seems to work again.

[bhousel]

Looking into this now.. What I've learned is that this gets broken when in tree.js, updateParents() calls parentWays()

call stack:

caller:

callee:

which is weird because it still knows how to actually call this.entity() :

[bhousel]

What I found is: If one adds if (!entity) entity = this.entities.proto[id]; after core/graph.js#L36, it seems to work again.

I spend most of the morning trying to understand what's going on, but got nowhere, so I added this code for now.. If we ever find what upstream bug in Chrome/V8 is causing this we can link to the ticket here and remove the line if it's ever fixed.

[tyrasd]

I went ahead and reported it upstream, because I really couldn't find anything related on their bug tracker: https://bugs.chromium.org/p/chromium/issues/detail?id=731193&can=1&q=prototype%20inheritance&colspec=ID%20Pri%20M%20Stars%20ReleaseBlock%20Component%20Status%20Owner%20Summary%20OS%20Modified

[bhousel]

Nice, thanks @tyrasd!

[dkewley]

I see this on Chrome OS 59.0.3071.91 too.

A suggestion: Consider updating default iD to have this patch so that those of us using Chrome on Linux or Chrome OS have a usable default iD. I ended up using iD master at http://preview.ideditor.com/master/ in order to be able to do any editing on Chrome OS. Thank you for finding and implementing a workaround on master!

[bhousel]

A suggestion: Consider updating default iD to have this patch so that those of us using Chrome on Linux or Chrome OS have a usable default iD.

Yes, I'm making a new release of iD tomorrow 👍

[tyrasd]

It's now fixed in chrome/v8: https://chromium-review.googlesource.com/c/539596/ 👍

[bhousel]

Great! I'm going to close this issue but I'll leave those extra lines of workaround code in the entity() function. We can remove them someday when Chrome 58/59 is a distant memory.