Having three quotes in a legend/data header field breaks the chart editing interface

[tomcardoso]

I had some data like this:

Category,Thing one,Thing two
Apple,12,24
Banana,10,9
Orange,1,6

And wanted to have Thing one display as "Thing" one in the legend, so I changed the data to this:

Category,""Thing" one",Thing two
Apple,12,24
Banana,10,9
Orange,1,6

… which breaks the interface for that chart.