[1.6.5][SSP] textutils.unserialize can not handle lua keywords

VERSION:
1.6.5 for Minecraft 1.7.10

DESCRIPTION:
If you serialize a table containing a lua keyword as a key (e.g. repeat, do…), unserializing the returned string will fail silently and return nil.

EXPECTED RESULT:
textutils.unserialize should return the table given to textutils.serialize.

REPRODUCTION STEPS:
Type in the following code:

x = {}
x['repeat'] = 1
y = textutils.unserialize(textutils.serialize(x))
print(tostring(y))

SCREENSHOT:

If I recall correctly, textutils.unserialise is pretty much just loadstring(). So you can imagine why this isn't working…
A possible fix would be to make textutils.serialise output ["do"] = 1 instead of do = 1 as shown in your screenshot.

I've tested it and it is possible to get it to work by wrapping the keyword in square brackets and quotes.
I think it would be simple to implement a check in textutils.serialize for the keywords and then add the square brackets and quotes.

Fixed in CC1.66