Trailing comma left when collapsing vertical argument list to single line

[staktrace]

Using rustfmt 0.99.2-nightly (5c9a2b6 2018-08-07) on this:

impl Foo {
    pub fn get_key(&self) -> Result<String, MailParseError> {
        Ok(
           try!(encoding::all::ISO_8859_1.decode(
               self.key,
               encoding::DecoderTrap::Strict,
           )).trim()
                .to_string(),
        )
    }
}

collapses the decode call onto a single line which is fine, but it keeps the trailing comma. My understanding is that the default value for trailing_comma is Vertical which should delete the comma.

[topecongiro]

This is somewhat expected - rustfmt is very deliberate about a trailing comma when formatting macro calls, because adding/removing it can break the code (some macros disallow a trailing comma, others require it).

[scampi]

@topecongiro as you mentioned in your comment, removing the comma could break some macros. Can we close this as a no fix then ?