rustfmt is not idempotent and not consistent

[datdenkikniet]

When formatting the following code,

mod test {
    extern "C" {fn test();}
}

The first diff suggested by rustfmt is

-    extern "C" {fn test();}
+    extern "C" {
+        fn test();    }

After running this formatting, the next suggestion is

-        fn test();    }
+        fn test();
+    }

The final result seems to be correct, but should most likely be applied at once, not in two steps.

Additionally, removing the mod block causes the changes to look like this:

extern "C" {fn test();}

-extern "C" {fn test();}
+extern "C" {
+    fn test();}

This change is idempotent, but I would expect the closing } to be moved to the next line (which is what happens if a whitespace is put in between the final ; and }).

[calebcartwright]

Thanks for the report, this is definitely a bug