Merge pull request #1775 from influxdb/fix-1764

fix #1764: panic index out of range

database.go

@@ -930,7 +930,7 @@ func (a seriesIDs) intersect(other seriesIDs) seriesIDs {
 	var i, j int
 
 	ids := make([]uint32, 0, len(l))
-	for i < len(l) {
+	for i < len(l) && j < len(r) {
 		if l[i] == r[j] {
 			ids = append(ids, l[i])
 			i++

internal_test.go

@@ -177,6 +177,88 @@ func TestCreateMeasurementsCommand_Errors(t *testing.T) {
 	}
 }
 
+// Test comparing seriesIDs for equality.
+func Test_seriesIDs_equals(t *testing.T) {
+	ids1 := seriesIDs{1, 2, 3}
+	ids2 := seriesIDs{1, 2, 3}
+	ids3 := seriesIDs{4, 5, 6}
+
+	if !ids1.equals(ids2) {
+		t.Fatal("expected ids1 == ids2")
+	} else if ids1.equals(ids3) {
+		t.Fatal("expected ids1 != ids3")
+	}
+}
+
+// Test intersecting sets of seriesIDs.
+func Test_seriesIDs_intersect(t *testing.T) {
+	// Test swaping l & r, all branches of if-else, and exit loop when 'j < len(r)'
+	ids1 := seriesIDs{1, 3, 4, 5, 6}
+	ids2 := seriesIDs{1, 2, 3, 7}
+	exp := seriesIDs{1, 3}
+	got := ids1.intersect(ids2)
+
+	if !exp.equals(got) {
+		t.Fatalf("exp=%v, got=%v", exp, got)
+	}
+
+	// Test exit for loop when 'i < len(l)'
+	ids1 = seriesIDs{1}
+	ids2 = seriesIDs{1, 2}
+	exp = seriesIDs{1}
+	got = ids1.intersect(ids2)
+
+	if !exp.equals(got) {
+		t.Fatalf("exp=%v, got=%v", exp, got)
+	}
+}
+
+// Test union sets of seriesIDs.
+func Test_seriesIDs_union(t *testing.T) {
+	// Test all branches of if-else, exit loop because of 'j < len(r)', and append remainder from left.
+	ids1 := seriesIDs{1, 2, 3, 7}
+	ids2 := seriesIDs{1, 3, 4, 5, 6}
+	exp := seriesIDs{1, 2, 3, 4, 5, 6, 7}
+	got := ids1.union(ids2)
+
+	if !exp.equals(got) {
+		t.Fatalf("exp=%v, got=%v", exp, got)
+	}
+
+	// Test exit because of 'i < len(l)' and append remainder from right.
+	ids1 = seriesIDs{1}
+	ids2 = seriesIDs{1, 2}
+	exp = seriesIDs{1, 2}
+	got = ids1.union(ids2)
+
+	if !exp.equals(got) {
+		t.Fatalf("exp=%v, got=%v", exp, got)
+	}
+}
+
+// Test removing one set of seriesIDs from another.
+func Test_seriesIDs_reject(t *testing.T) {
+	// Test all branches of if-else, exit loop because of 'j < len(r)', and append remainder from left.
+	ids1 := seriesIDs{1, 2, 3, 7}
+	ids2 := seriesIDs{1, 3, 4, 5, 6}
+	exp := seriesIDs{2, 7}
+	got := ids1.reject(ids2)
+
+	if !exp.equals(got) {
+		t.Fatalf("exp=%v, got=%v", exp, got)
+	}
+
+	// Test exit because of 'i < len(l)'.
+	ids1 = seriesIDs{1}
+	ids2 = seriesIDs{1, 2}
+	exp = seriesIDs{}
+	got = ids1.reject(ids2)
+
+	if !exp.equals(got) {
+		t.Fatalf("exp=%v, got=%v", exp, got)
+	}
+}
+
 // MustParseExpr parses an expression string and returns its AST representation.
 func MustParseExpr(s string) influxql.Expr {
 	expr, err := influxql.ParseExpr(s)