fix internal error when stmt has doc attribute (#3985)

Author: rchaser53

src/comment.rs

@@ -1565,7 +1565,8 @@ pub(crate) fn recover_comment_removed(
     context: &RewriteContext<'_>,
 ) -> Option<String> {
     let snippet = context.snippet(span);
-    if snippet != new && changed_comment_content(snippet, &new) {
+    let includes_comment = contains_comment(snippet);
+    if snippet != new && includes_comment && changed_comment_content(snippet, &new) {
         // We missed some comments. Warn and keep the original text.
         if context.config.error_on_unformatted() {
             context.report.append(

src/stmt.rs

@@ -107,5 +107,7 @@ fn format_stmt(
         }
         ast::StmtKind::Mac(..) | ast::StmtKind::Item(..) => None,
     };
-    result.and_then(|res| recover_comment_removed(res, stmt.span(), context))
+    result.and_then(|res| {
+        recover_comment_removed(res, stmt.span(), context)
+    })
 }

tests/source/issue-3981.rs

@@ -0,0 +1,7 @@
+// rustfmt-normalize_doc_attributes: true
+
+#[doc = " item"]
+fn main() {
+    #[doc = " stmt"]
+    let _=( );
+}

tests/target/issue-3981.rs

@@ -0,0 +1,7 @@
+// rustfmt-normalize_doc_attributes: true
+
+/// item
+fn main() {
+    /// stmt
+    let _ = ();
+}