cgen: fix match expression with complex boolean conditions

vlib/v/gen/c/cgen.v

@@ -3808,7 +3808,9 @@ fn (mut g Gen) match_expr_classic(node ast.MatchExpr, is_expr bool, cond_var str
 				} else {
 					g.write(cond_var)
 					g.write(' == ')
+					g.write('(')
 					g.expr(expr)
+					g.write(')')
 				}
 			}
 			if is_expr && tmp_var.len == 0 {

vlib/v/tests/match_with_complex_exprs_in_branches_test.v

@@ -4,7 +4,9 @@ fn test_match_with_array_map_in_branches() {
 	arr := Arr([0, 1])
 	ret := match arr {
 		[]int {
-			arr.map(fn(s int) string { return s.str() }).str()
+			arr.map(fn (s int) string {
+				return s.str()
+			}).str()
 		}
 		else {
 			''
@@ -29,3 +31,14 @@ fn test_match_expr_of_multi_expr_stmts() {
 	println(ret)
 	assert ret == 2
 }
+
+fn test_match_expression_on_complex_bool_conditions() {
+	s := 'hello'
+	x := match true {
+		s[1] == `e` { 'first' }
+		(s[1] == `e`) { 'second' }
+		else { 'not found' }
+	}
+	println(x)
+	assert x == 'first'
+}