A single task can launch many times if running multiple times while window is loading

[Tyriar]

I had a particularly slow start up just now and I hit ctrl+shift+b a bunch of times, once everything settled it launched 3x for each task:

Version: 1.55.0-insider (user setup)
Commit: 0477036
Date: 2021-03-05T15:40:03.281Z
Electron: 11.3.0
Chrome: 87.0.4280.141
Node.js: 12.18.3
V8: 8.7.220.31-electron.0
OS: Windows_NT x64 10.0.19042

[alexr00]

This is going to require a lot of refactoring to solve. Will try to tackle next debt week.

[alexr00]

Found a simple way to solve it.

[Tyriar]

If I try to repro now the default build task no longer works, ctrl+shift+b only shows this now:

[alexr00]

I had reverted the fix since it broke something else. Will try another fix.

[alexr00]

Re-applied the fix and fixed the test that it revealed a bug in.

[Tyriar]

@alexr00 the issue I hit is still happening in:

Version: 1.56.0-insider (user setup)
Commit: 633562d
Date: 2021-04-26T05:14:38.204Z
Electron: 12.0.4
Chrome: 89.0.4389.114
Node.js: 14.16.0
V8: 8.9.255.24-electron.0
OS: Windows_NT x64 10.0.19042

Repro:

1. Reload vscode repo
2. ctrl+shift+b quickly

[meganrogge]

/duplicate #159640