DomainMatcher: Fix CompactDomainMatcher rule indices (#5934)

Fixes https://github.com/XTLS/Xray-core/pull/5924

common/geodata/domain_matcher_test.go

@@ -0,0 +1,50 @@
+package geodata
+
+import (
+	"path/filepath"
+	"reflect"
+	"slices"
+	"testing"
+
+	"github.com/xtls/xray-core/common/geodata/strmatcher"
+)
+
+func TestCompactDomainMatcher_PreservesCustomRuleIndices(t *testing.T) {
+	factory := &CompactDomainMatcherFactory{shared: make(map[string]strmatcher.MatcherGroup)}
+	matcher, err := factory.BuildMatcher([]*DomainRule{
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Full, Value: "example.com"}}},
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Domain, Value: "example.com"}}},
+	})
+	if err != nil {
+		t.Fatalf("BuildMatcher() failed: %v", err)
+	}
+
+	got := matcher.Match("example.com")
+	slices.Sort(got)
+
+	want := []uint32{0, 1}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("Match() = %v, want %v", got, want)
+	}
+}
+
+func TestCompactDomainMatcher_PreservesMixedRuleIndices(t *testing.T) {
+	t.Setenv("xray.location.asset", filepath.Join("..", "..", "resources"))
+
+	factory := &CompactDomainMatcherFactory{shared: make(map[string]strmatcher.MatcherGroup)}
+	matcher, err := factory.BuildMatcher([]*DomainRule{
+		{Value: &DomainRule_Geosite{Geosite: &GeoSiteRule{File: DefaultGeoSiteDat, Code: "CN"}}},
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Full, Value: "163.com"}}},
+	})
+	if err != nil {
+		t.Fatalf("BuildMatcher() failed: %v", err)
+	}
+
+	got := matcher.Match("163.com")
+	slices.Sort(got)
+
+	want := []uint32{0, 1}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("Match() = %v, want %v", got, want)
+	}
+}