From 20150352187388781b1f64476f508954a369e204 Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Mon, 22 Sep 2025 16:25:13 -0300
Subject: [PATCH] cgen: fix match with option cast expr (fix #25342) (#25372)

---
 vlib/v/gen/c/match.v                          |  3 ++
 .../options/option_match_case_cast_test.v     | 49 +++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 vlib/v/tests/options/option_match_case_cast_test.v

diff --git a/vlib/v/gen/c/match.v b/vlib/v/gen/c/match.v
index 6d61ff66f..b11284e54 100644
--- a/vlib/v/gen/c/match.v
+++ b/vlib/v/gen/c/match.v
@@ -585,6 +585,9 @@ fn (mut g Gen) match_must_reset_if(node ast.Expr) bool {
 		ast.CallExpr {
 			node.or_block.kind != .absent
 		}
+		ast.CastExpr {
+			node.typ.has_flag(.option)
+		}
 		ast.InfixExpr {
 			g.match_must_reset_if(node.left) || g.match_must_reset_if(node.right)
 		}
diff --git a/vlib/v/tests/options/option_match_case_cast_test.v b/vlib/v/tests/options/option_match_case_cast_test.v
new file mode 100644
index 000000000..f4fc0ec93
--- /dev/null
+++ b/vlib/v/tests/options/option_match_case_cast_test.v
@@ -0,0 +1,49 @@
+module main
+
+type SecondTokenizerValue = []rune | Keyword
+
+enum AdvancedTokenType {
+	identifier
+	keyword
+	newline
+}
+
+struct SecondTokenizerToken {
+	type  AdvancedTokenType
+	value ?SecondTokenizerValue
+}
+
+enum Keyword {
+	module
+	import
+}
+
+fn test_main() {
+	mut tokens := []SecondTokenizerToken{}
+	tokens << SecondTokenizerToken{
+		type:  AdvancedTokenType.keyword
+		value: Keyword.module
+	}
+	build_ast(tokens) or { assert err.msg() == 'Handling module' }
+}
+
+struct RootAST {
+	module []rune
+}
+
+fn build_ast(tokens []SecondTokenizerToken) !RootAST {
+	token := tokens[0]
+	match true {
+		token.type == .keyword && token.value == ?SecondTokenizerValue(Keyword.module) {
+			return error('Handling module')
+		}
+		token.type == .keyword && token.value == ?SecondTokenizerValue(Keyword.import) {
+			return error('Handling import')
+		}
+		else {
+			return error('else')
+		}
+	}
+
+	return error('Not implemented')
+}
-- 
2.39.5