Bug in toRomanNumeral

[jkr]

9 (and numbers ending with a 9) will translate to "IXIV". The code in Text.Pandoc.Shared is currently

...
_ | x >= 9    -> "IX" ++ toRomanNumeral (x - 5)
...

I imagine it should be

...
_ | x >= 9    -> "IX" ++ toRomanNumeral (x - 9)
...

Although, since 9 is the only number it applies to (10 and larger have a different rule), I'm not sure if the string addition is necessary at all. I.e., it seems like you could get away with the following, and leave less room for error:

...
_ | x >= 9    -> "IX"
...

[jgm]

Oh, that's a bad one. Amazing how long it has gone undetected! Thank you.