Trapping errors on Rename and perhaps other dialogs?

[rdstern]

@N-thony and perhaps @lilyclements I have been very happy with the improvements in the Rename dialog.

Now I have been trying to make it crash and have suceeded, but I had to try quite hard:

a) In the dialog, as shown, I first made 2 names the same. It just gave me a sensible error message.
b) Then I made some spaces in names and it put dots in for me. Even better!
c) Then I started a name with numbers and that gave me the dreaded exception error and I'm now going to have to crash out.

Now we could try and catch this too - which we do on the simple single rename dialog. Maybe we should - as starting with an illegal value is pretty likely from R-Instat users.

But I assume the Rename with could also generate an error similarly on occasion, and it will be hard to trap each of those?

I'm wondering if the @N-thony undo could come to our rescue here? Could it trap a serious error, like this give a general message, like "Serious error generated, so keeping the dataframe as before." Then simply do an undo, so keeping the "old" data frame?