Rustfmt formats macro to exceed line length

[YaLTeR]

I have this macro that I formatted manually:

        macro_rules! touch_value {
            ($func:ident, $value:expr) => {{
                let result =
                    API::get_cached().$func(
                        self,
                        key.as_ptr(),
                        $value,
                        ffi::VSPropAppendMode::paTouch
                    );
                debug_assert!(result == 0);
            }};
        }

Running rustfmt (or rustfmt --check) suggests the following diff:

         macro_rules! touch_value {
             ($func:ident, $value:expr) => {{
                 let result =
-                    API::get_cached().$func(
-                        self,
-                        key.as_ptr(),
-                        $value,
-                        ffi::VSPropAppendMode::paTouch
-                    );
+                    API::get_cached().$func(self, key.as_ptr(), $value, ffi::VSPropAppendMode::paTouch);
                 debug_assert!(result == 0);
             }};
         }

Which makes the line exceed the line length limit. Previously this also resulted in rustfmt complaining about it exceeding the line length limit (so basically it breaks the formatting and then complains about it).

While putting #[cfg_attr(rustfmt, rustfmt_skip)] ontop prevents the issue from happening, maybe rustfmt shouldn't reformat the macro in this case?

Update: rustfmt 0.99.2-nightly (5c9a2b6 2018-08-07) although this has been happening for several months (since that macro appeared in the codebase).