Fix checking if newline is needed before else in let-else statement (#5901)

Author: rhysd

src/items.rs

@@ -127,8 +127,17 @@ impl Rewrite for ast::Local {
 
             if let Some(block) = else_block {
                 let else_kw_span = init.span.between(block.span);
+                let init_str = if !attrs_str.is_empty() {
+                    // Strip attributes to check if newline is needed before the else keyword from
+                    // the initializer part. (#5901)
+                    result
+                        .strip_prefix(&attrs_str)
+                        .map_or(result.as_str(), str::trim_start)
+                } else {
+                    result.as_str()
+                };
                 let force_newline_else = pat_str.contains('\n')
-                    || !same_line_else_kw_and_brace(&result, context, else_kw_span, nested_shape);
+                    || !same_line_else_kw_and_brace(init_str, context, else_kw_span, nested_shape);
                 let else_kw = rewrite_else_kw_with_comments(
                     force_newline_else,
                     true,

tests/source/let_else.rs

@@ -160,3 +160,8 @@ fn with_trailing_try_operator() {
     // Maybe this is a workaround?
     let Ok(Some(next_bucket)) = ranking_rules[cur_ranking_rule_index].next_bucket(ctx, logger, &ranking_rule_universes[cur_ranking_rule_index]) else { return };
 }
+
+fn issue5901() {
+    #[cfg(target_os = "linux")]
+    let Some(x) = foo() else { return; };
+}

tests/target/let_else.rs

@@ -252,3 +252,10 @@ fn with_trailing_try_operator() {
         return;
     };
 }
+
+fn issue5901() {
+    #[cfg(target_os = "linux")]
+    let Some(x) = foo() else {
+        return;
+    };
+}