return when span is start span

Author: rchaser53

src/missed_spans.rs

@@ -100,6 +100,10 @@ impl<'a> FmtVisitor<'a> {
         }
 
         if snippet.trim().is_empty() && !out_of_file_lines_range!(self, span) {
+            if self.is_start_span(span) {
+                return;
+            }
+
             // Keep vertical spaces within range.
             self.push_vertical_spaces(count_newlines(snippet));
             process_last_snippet(self, "", snippet);

src/visitor.rs

@@ -46,6 +46,10 @@ impl SnippetProvider {
         Some(&self.big_snippet[start_index..end_index])
     }
 
+    pub(crate) fn is_start_span(&self, span: Span) -> bool {
+        span.lo().to_usize() == self.start_pos
+    }
+
     pub(crate) fn new(start_pos: BytePos, end_pos: BytePos, big_snippet: Rc<String>) -> Self {
         let start_pos = start_pos.to_usize();
         let end_pos = end_pos.to_usize();
@@ -751,6 +755,10 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
         self.opt_snippet(span).unwrap()
     }
 
+    pub(crate) fn is_start_span(&'b self, span: Span) -> bool {
+        self.snippet_provider.is_start_span(span)
+    }
+
     // Returns true if we should skip the following item.
     pub(crate) fn visit_attrs(&mut self, attrs: &[ast::Attribute], style: ast::AttrStyle) -> bool {
         for attr in attrs {