MultiSelect broken for empty array

[MiselKING]

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Plunkr Case (Bug Reports)
Please demonstrate your case at stackblitz by using the issue template below. Issues without a test case have much less possibility to be reviewed in detail and assisted.

https://stackblitz.com/edit/github-zhgb7m

(don't forget to update "primeng" to 8.0.1 before trying)

Current behavior
When I try to open "multiselect" dropdown with no items it crashes and console output shows:

ERROR TypeError: Cannot read property 'length' of undefined
at MultiSelect.isAllChecked (multiselect.ts:461)

Expected behavior
I expect it to work properly (not crash).

Minimal reproduction of the problem with instructions
Try and open "multiselect" in the provided stackblitz example above. It will crash. Although, it seems that with version 8.0.0 it is working fine, so the issue seems to have been introduced with the version 8.0.1.

What is the motivation / use case for changing the behavior?
I'd like to use "multiselect" in my app ;)

Please tell us about your environment:
Windows 10 x64 v1809

• Angular version: 8.1.1

• PrimeNG version: 8.0.1

• Browser: Chrome 75.0.3770.100 ; didn't try others

• Language: TypeScript 3.4.5

• Node (for AoT issues): node --version = 12.6.0

[kenImas]

+1

We are also experiencing this issue. Primeng 8.0.0 works, but with 8.0.1 it does not!

[thaylongs]

+1 with Primeng 8.0.1

[MiselKING]

It seems that this will be resolved as a part of 8.0.2 release. Reference issue:
#7950
Therefore, I am closing this issue...

[dandohotaru]

in the meantime, turning off the toggle all feature, makes the problem go away...
of course, this is applicable only if you can live without that feature till 8.0.2 patch comes out :)

<p-multiSelect [showToggleAll]="false" ...>