Fix error on deleting tab

[HiroyasuNishiyama]

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Proposed changes

Deleting tab (workspace) from following tab information edit panel causes
Uncaught TypeError: Cannot read property 'label' of undefined error.

This seems to be caused by refreshing sidebar of deleted tab on closing panel.

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the forum/slack team.
• I have run grunt to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality

[coveralls]

Coverage remained the same at 77.525% when pulling 12c9207 on node-red-hitachi:fix-delete-tab into e674d92 on node-red:dev.

[dceejay]

Is this same as fix e674d92 ?

[knolleary]

@dceejay no - similar looking error, but a different cause. The proposed fix certain stops it. Just want to check its putting the check in the right place.

But both this issue and the fix you refer to highlight the need to add some checks to treeList to prevent it trying to operate on items that are no longer in the tree (thats the common element between the two issues).

[knolleary]

Having merged this, I noticed we were refreshing the info sidebar twice when the edit dialog was closed.

In tracking that down, I found the proper fix for this issue - 1f2c0a7

We should only refresh the sidebar with the workspace if there is nothing else selected in the workspace.