Constructing invalid dates can lead to infinite recursion

[alan-knight]

I ran into this attempting to naively just parse back whatever we had generated for a date format. One of the valid date formats is just "day". So January 27, 2012, prints as "27". That ends up in an infinite recursion if you parse it. As does

main() {
  var x = new Date(0,0,27,0,0,0,0,false);
  print(x);
}

That's not, I think, a representable date if we're counting from 1970, but it still shouldn't crash the VM.

[dgrove]

cc @lrhn.
cc @iposva-google.
Added Area-Library, Triaged labels.

[iposva-google]

cc @floitschG.

[floitschG]

Set owner to @floitschG.
Added Accepted label.

[floitschG]

I tried to reproduce, but don't get any infinite recursion.
There is a bug that printed the year 0 as "null" (just uploaded a CL), but no infinite loop.
Could you please verify if your example still goes into recursion, and if yes, contact me with more information.

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Added NeedsInfo label.

[alan-knight]

If I run it in the editor, on either Linux 64-bit or Mac 64-bit, then it runs for about 10 seconds and then exits with status code 139 with nothing printed. If I run it on a current stand-alone VM on Linux then I get an illegal arguments exception thrown. That might indicate that it's fixed in the current builds, but that's not clear to me.

[floitschG]

I can reproduce now.
Given that the CPU spikes to 100% during the ~10secs I suspect it's a VM bug, when it is run with the debugger enabled.

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Removed the owner.
Removed Area-Library label.
Added Area-VM, Triaged labels.

[iposva-google]

Set owner to @mraleph.

[mraleph]

Does not cause any CPU spikes now even when run from the editor.

However it outputs:

-0001-12-27 00:00:00.000

which does not seem to correct.

Assigning to Florian.

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Set owner to @floitschG.
Added this to the M1 milestone.

[floitschG]

Looks correct to me. What should it be?

[alan-knight]

What's correct to print there does seem rather questionable. In this case it's wrapping the month around and compensating in the year. So providing zero as a month gives you December of the previous year. Since the year is zero, it's printing negative 1 for the year. In the same way
main() {
  var x = new Date(0,53,27,0,0,0,0,false);
  print(x);
}
prints
0004-05-27 00:00:00.000

There is no year zero, so the printing isn't really correct, but I think printing dates around that period isn't really the issue so much as being able to have zero fields for data that isn't specified, so this works well enough for me.

[floitschG]

Closing as assumed-stale.

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Added AssumedStale label.