[go_router] Secured empty matches in canPop

[aprzedecki]

If current configuration matches is empty, canPop throws exceptions instead of quit properly

StateError: Bad state: No element
  App                 0x1086b3e80  List.last (growable_array.dart:349)
  App                 0x108996274  GoRouterDelegate.canPop (delegate.dart:84)
  App                 0x1089961bc  GoRouter.canPop (router.dart:330)
  App                 0x10899615c  BuildContextExtension|get#_shouldPop (build_context_extensions.dart:40)

• if there are no elements, poping page throws an error

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[chunhtai]

Thanks for fixing it! The fix lgtm, can you add a test to make sure we don't regress this change? it is also our policy to only accept change with a test.

While you at it, can you also bump the pubspec.yaml and changelog?

[aprzedecki]

Thanks for fixing it! The fix lgtm, can you add a test to make sure we don't regress this change? it is also our policy to only accept change with a test.

While you at it, can you also bump the pubspec.yaml and changelog?

Sure thing.
Ready 👌

[aprzedecki]

@chunhtai are we good to go ?

[aprzedecki]

@ditman maybe you can help?

[chunhtai]

LGTM

[hannah-hyj]

LGTM