From 1dc62a5a66970258099937706f4898aff5521790 Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Fri, 19 Aug 2022 14:44:59 +0800
Subject: [PATCH] ast: fix string interpolation fmt with result call (#15467)

---
 vlib/v/ast/str.v                                 | 2 +-
 vlib/v/fmt/tests/string_intp_with_result_keep.vv | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/fmt/tests/string_intp_with_result_keep.vv

diff --git a/vlib/v/ast/str.v b/vlib/v/ast/str.v
index cf9372ea8b..143e54ef0b 100644
--- a/vlib/v/ast/str.v
+++ b/vlib/v/ast/str.v
@@ -210,7 +210,7 @@ pub fn (lit &StringInterLiteral) get_fspec_braces(i int) (string, bool) {
 				}
 				CallExpr {
 					if sub_expr.args.len != 0 || sub_expr.concrete_types.len != 0
-						|| sub_expr.or_block.kind == .propagate_option
+						|| sub_expr.or_block.kind in [.propagate_option, .propagate_result]
 						|| sub_expr.or_block.stmts.len > 0 {
 						needs_braces = true
 					} else if sub_expr.left is CallExpr {
diff --git a/vlib/v/fmt/tests/string_intp_with_result_keep.vv b/vlib/v/fmt/tests/string_intp_with_result_keep.vv
new file mode 100644
index 0000000000..3a052ab533
--- /dev/null
+++ b/vlib/v/fmt/tests/string_intp_with_result_keep.vv
@@ -0,0 +1,7 @@
+fn err() !u8 {
+	return 1
+}
+
+fn main() {
+	println('${err()!}')
+}