From fd384dff4811a4f0258225e158ebb9a7327f01ac Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Tue, 25 Jun 2024 19:17:57 -0300
Subject: [PATCH] cgen: fix assert checking fn option ret with `none` (#21726)

---
 vlib/v/gen/c/cgen.v                      | 6 ++++--
 vlib/v/gen/c/ctempvars.v                 | 1 +
 vlib/v/tests/assert_fn_ret_option_test.v | 8 ++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)
 create mode 100644 vlib/v/tests/assert_fn_ret_option_test.v

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index 89aa4762c8..be728e7b6b 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -2045,8 +2045,10 @@ fn (mut g Gen) expr_with_tmp_var(expr ast.Expr, expr_typ ast.Type, ret_typ ast.T
 				}
 			} else {
 				simple_assign =
-					(expr is ast.SelectorExpr || (expr is ast.Ident && !expr.is_auto_heap()))
-					&& ret_typ.is_ptr() && expr_typ.is_ptr() && expr_typ.has_flag(.option)
+					((expr is ast.SelectorExpr || (expr is ast.Ident && !expr.is_auto_heap()))
+					&& ret_typ.is_ptr() && expr_typ.is_ptr() && expr_typ.has_flag(.option))
+					|| (expr_typ == ret_typ && !(expr_typ.has_option_or_result()
+					&& (expr_typ.is_ptr() || expr is ast.LambdaExpr)))
 				// option ptr assignment simplification
 				if simple_assign {
 					g.write('${tmp_var} = ')
diff --git a/vlib/v/gen/c/ctempvars.v b/vlib/v/gen/c/ctempvars.v
index b19b8cac5d..a0fdd5c6dd 100644
--- a/vlib/v/gen/c/ctempvars.v
+++ b/vlib/v/gen/c/ctempvars.v
@@ -22,4 +22,5 @@ fn (mut g Gen) gen_ctemp_var(tvar ast.CTempVar) {
 	g.write('${styp} ${tvar.name} = ')
 	g.expr(tvar.orig)
 	g.writeln(';')
+	g.set_current_pos_as_last_stmt_pos()
 }
diff --git a/vlib/v/tests/assert_fn_ret_option_test.v b/vlib/v/tests/assert_fn_ret_option_test.v
new file mode 100644
index 0000000000..6070c5cfce
--- /dev/null
+++ b/vlib/v/tests/assert_fn_ret_option_test.v
@@ -0,0 +1,8 @@
+fn find_token_by_id() ?int {
+	return none
+}
+
+fn test_main() {
+	assert find_token_by_id() == none
+	println('done')
+}