fix bugs with: Failed to handle key ... Cannot read property 'substring' of undefined

[elazarcoh]

What this PR does / why we need it:
I think it should fix all the lately reported bugs with "Failed to handle key ... Cannot read property 'substring' of undefined"

Which issue(s) this PR fixes
fixes #7512
and lots more of them.

Special notes for your reviewer:

[elazarcoh]

@J-Fields this still might have a race-condition.
Maybe it's safer to do

public async historyBack(): Promise<void> {
    //  ...
      this.historyIndex = Math.max(this.historyIndex - 1, 0);
   // ...
}

public async historyForward(): Promise<void> {
       // ....
      this.historyIndex = Math.min(this.historyIndex + 1, historyEntries.length - 1);
  // ...
}

[J-Fields]

Can you elaborate? I'm not sure what race condition you're referring to

[J-Fields]

Actually, I want to cut a release and this seems very reasonable so I'm gonna merge - if you still have concerns please let me know and we can make sure they're addressed