Merge pull request rust-lang#2972 from crw5996/fix-optional-arg-condensing

Fix optional arg condensing

Author: nrc

src/patterns.rs

@@ -336,29 +336,28 @@ fn rewrite_tuple_pat(
         ));
         pat_vec.insert(pos, dotdot);
     }
-
     if pat_vec.is_empty() {
         return Some(format!("{}()", path_str.unwrap_or_default()));
     }
-
     let wildcard_suffix_len = count_wildcard_suffix_len(context, &pat_vec, span, shape);
-    let (pat_vec, span) = if context.config.condense_wildcard_suffixes() && wildcard_suffix_len >= 2
-    {
-        let new_item_count = 1 + pat_vec.len() - wildcard_suffix_len;
-        let sp = pat_vec[new_item_count - 1].span();
-        let snippet = context.snippet(sp);
-        let lo = sp.lo() + BytePos(snippet.find_uncommented("_").unwrap() as u32);
-        pat_vec[new_item_count - 1] = TuplePatField::Dotdot(mk_sp(lo, lo + BytePos(1)));
-        (
-            &pat_vec[..new_item_count],
-            mk_sp(span.lo(), lo + BytePos(1)),
-        )
-    } else {
-        (&pat_vec[..], span)
-    };
+    let (pat_vec, span, condensed) =
+        if context.config.condense_wildcard_suffixes() && wildcard_suffix_len >= 2 {
+            let new_item_count = 1 + pat_vec.len() - wildcard_suffix_len;
+            let sp = pat_vec[new_item_count - 1].span();
+            let snippet = context.snippet(sp);
+            let lo = sp.lo() + BytePos(snippet.find_uncommented("_").unwrap() as u32);
+            pat_vec[new_item_count - 1] = TuplePatField::Dotdot(mk_sp(lo, lo + BytePos(1)));
+            (
+                &pat_vec[..new_item_count],
+                mk_sp(span.lo(), lo + BytePos(1)),
+                true,
+            )
+        } else {
+            (&pat_vec[..], span, false)
+        };
 
     // add comma if `(x,)`
-    let add_comma = path_str.is_none() && pat_vec.len() == 1 && dotdot_pos.is_none();
+    let add_comma = path_str.is_none() && pat_vec.len() == 1 && dotdot_pos.is_none() && !condensed;
     let path_str = path_str.unwrap_or_default();
     let pat_ref_vec = pat_vec.iter().collect::<Vec<_>>();
 

tests/source/issue-2955.rs

@@ -0,0 +1,6 @@
+// rustfmt-condense_wildcard_suffixes: true
+fn main() {
+    match (1, 2, 3) {
+        (_, _, _) => (),
+    }
+}

tests/target/issue-2955.rs

@@ -0,0 +1,6 @@
+// rustfmt-condense_wildcard_suffixes: true
+fn main() {
+    match (1, 2, 3) {
+        (..) => (),
+    }
+}