checker: remove () from match branch exprs (fix #25950) (#25952)

Author: kbkpbot

vlib/v/checker/match.v

@@ -238,6 +238,11 @@ fn (mut c Checker) match_expr(mut node ast.MatchExpr) ast.Type {
 			}
 		}
 
+		for mut expr in branch.exprs {
+			// (expr) => expr
+			expr = expr.remove_par()
+		}
+
 		if !c.pref.translated && !c.file.is_translated {
 			// check for always true/false match branch
 			for mut expr in branch.exprs {

vlib/v/tests/match_branch_par_expr_test.v

@@ -0,0 +1,32 @@
+module main
+
+enum TokenType {
+	null
+	word
+	get_word
+	set_word
+	lit_word
+	int_value
+	dec_value
+	bin_value
+	str_value
+	block_start
+	block_end
+	expr_start
+	expr_end
+	comment
+}
+
+fn test_match_branch_par_expr() {
+	t := TokenType.word
+	s := match t {
+		(TokenType.null) { '' }
+		(TokenType.word) { 'a' }
+		(TokenType.get_word) { 'b' }
+		(TokenType.set_word) { 'c' }
+		(TokenType.lit_word) { 'd' }
+		else { 'other' }
+	}
+
+	assert s == 'a'
+}