From 78287b12cc6ff6aa4acf2b95c2dfa741f0d5f869 Mon Sep 17 00:00:00 2001
From: Albert Meltzer <7529386+kitbellew@users.noreply.github.com>
Date: Sun, 28 May 2023 20:53:26 -0700
Subject: [PATCH] ScalametaParser: constrain NL before block in arg

Turns out it's only in scala2 and only after parens.
---
 .../scala/scala/meta/internal/parsers/ScalametaParser.scala  | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scalameta/parsers/shared/src/main/scala/scala/meta/internal/parsers/ScalametaParser.scala b/scalameta/parsers/shared/src/main/scala/scala/meta/internal/parsers/ScalametaParser.scala
index a660c9a44f..33e76bfe54 100644
--- a/scalameta/parsers/shared/src/main/scala/scala/meta/internal/parsers/ScalametaParser.scala
+++ b/scalameta/parsers/shared/src/main/scala/scala/meta/internal/parsers/ScalametaParser.scala
@@ -2312,7 +2312,10 @@ class ScalametaParser(input: Input)(implicit dialect: Dialect) { parser =>
       }
       token match {
         case _: Dot | _: OpenDelim | _: Underscore => getRest()
-        case _: LF if peekToken.is[LeftBrace] => next(); getRest()
+        // see ArgumentExprs in:
+        // https://scala-lang.org/files/archive/spec/2.13/13-syntax-summary.html#context-free-syntax
+        case _: LF if !isBrace && !dialect.allowSignificantIndentation && tryAhead[LeftBrace] =>
+          getRest()
         case _ =>
           makeTupleTerm { arg =>
             val res = maybeAnonymousFunction(arg)