From 19be2283f0be540b554a465222ed9adf22eb0d19 Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Sun, 27 Apr 2025 22:13:07 -0300
Subject: [PATCH] cgen: fix codegen for handling multiple return result type on
 call (fix #24341) (#24344)

---
 vlib/v/gen/c/fn.v                   |  2 +-
 vlib/v/tests/fns/call_result_test.v | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/tests/fns/call_result_test.v

diff --git a/vlib/v/gen/c/fn.v b/vlib/v/gen/c/fn.v
index 40aebca4e..ed4987bd0 100644
--- a/vlib/v/gen/c/fn.v
+++ b/vlib/v/gen/c/fn.v
@@ -1048,7 +1048,7 @@ fn (mut g Gen) call_expr(node ast.CallExpr) {
 					g.write('\n ${cur_line}')
 				}
 			} else {
-				if !g.inside_or_block && g.last_tmp_call_var.len > 0 {
+				if !g.inside_or_block && g.last_tmp_call_var.len > 0 && !cur_line.contains(' = ') {
 					g.write('\n\t*(${unwrapped_styp}*)${g.last_tmp_call_var.pop()}.data = ${cur_line}(*(${unwrapped_styp}*)${tmp_opt}.data)')
 				} else {
 					g.write('\n ${cur_line}(*(${unwrapped_styp}*)${tmp_opt}.data)')
diff --git a/vlib/v/tests/fns/call_result_test.v b/vlib/v/tests/fns/call_result_test.v
new file mode 100644
index 000000000..e937eef61
--- /dev/null
+++ b/vlib/v/tests/fns/call_result_test.v
@@ -0,0 +1,27 @@
+module main
+
+const x = c(c(c('123') or { '456' }) or { '444' }) or { 'xx' }
+
+fn a(s string) ?string {
+	if s == 'b' {
+		return 'a'
+	} else {
+		return none
+	}
+}
+
+fn b(s string) ?string {
+	if s == 'a' {
+		return 'b'
+	} else {
+		return none
+	}
+}
+
+fn c(s string) !string {
+	return a(s) or { b(s) or { 'c' } }
+}
+
+fn test_main() {
+	assert x == 'c'
+}
-- 
2.39.5