Make is_mod_decl more accommodating

Fixes #2403 (I think)

Cargo.lock

@@ -294,7 +294,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "rustfmt-nightly"
-version = "0.3.7"
+version = "0.3.8"
 dependencies = [
  "cargo_metadata 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive-new 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 
 name = "rustfmt-nightly"
-version = "0.3.7"
+version = "0.3.8"
 authors = ["Nicholas Cameron <ncameron@mozilla.com>", "The Rustfmt developers"]
 description = "Tool to find and fix Rust formatting issues"
 repository = "https://github.com/rust-lang-nursery/rustfmt"

src/codemap.rs

@@ -48,8 +48,8 @@ pub trait LineRangeUtils {
 
 impl SpanUtils for CodeMap {
     fn span_after(&self, original: Span, needle: &str) -> BytePos {
-        let snippet = self.span_to_snippet(original).unwrap();
+        let snippet = self.span_to_snippet(original).expect("Bad snippet");
-        let offset = snippet.find_uncommented(needle).unwrap() + needle.len();
+        let offset = snippet.find_uncommented(needle).expect("Bad offset") + needle.len();
 
         original.lo() + BytePos(offset as u32)
     }

src/visitor.rs

@@ -44,10 +44,7 @@ pub fn filter_inline_attrs(attrs: &[ast::Attribute], outer_span: Span) -> Vec<as
 /// Returns true for `mod foo;`, false for `mod foo { .. }`.
 fn is_mod_decl(item: &ast::Item) -> bool {
     match item.node {
-        ast::ItemKind::Mod(ref m) => {
+        ast::ItemKind::Mod(ref m) => m.inner.hi() != item.span.hi(),
-            !(m.inner.lo() == BytePos(0) && m.inner.hi() == BytePos(0))
-                && m.inner.hi() != item.span.hi()
-        }
         _ => false,
     }
 }