.

wcfs/internal/xbtree/δbtail_test.go

@@ -834,6 +834,19 @@ func xverifyΔBTail_Update1(t *testing.T, subj string, db *zodb.DB, treeRoot zod
 	δbtail.assertTrack(t, "2", trackSet2, ø)
 
 
+	// assert δtkeycov == δ(tkeyCov1, tkeyCov2)
+	δtkeycovOK := tkeyCov2.Difference(tkeyCov1)
+	fmt.Printf("tkeyCov1: %s\n", tkeyCov1)
+	fmt.Printf("tkeyCov2: %s\n", tkeyCov2)
+	fmt.Printf("δtkeycov: %s\n", δtkeycovOK)
+	δtkeycov := &RangedKeySet{}
+	if __, ok := δB1.ByRoot[treeRoot]; ok {
+		δtkeycov = __.δtkeycov1
+	}
+	if !δtkeycov.Equal(δtkeycovOK) {
+		badf("δtkeycov wrong:\nhave: %s\nwant: %s", δtkeycov, δtkeycovOK)
+	}
+
 	// assert δB.ByRoot == {treeRoot -> ...}  if δTok != ø
 	//                  == ø                  if δTok == ø
 	rootsOK := SetOid{}
@@ -852,13 +865,6 @@ func xverifyΔBTail_Update1(t *testing.T, subj string, db *zodb.DB, treeRoot zod
 		return
 	}
 
-	// assert δtkeycov == δ(tkeyCov1, tkeyCov2)
-	δtkeycovOK := tkeyCov2.Difference(tkeyCov1)
-	δtkeycov := δB1.ByRoot[treeRoot].δtkeycov1
-	if !δtkeycov.Equal(δtkeycovOK) {
-		badf("δtkeycov wrong:\nhave: %s\nwant: %s", δtkeycov, δtkeycovOK)
-	}
-
 
 	// δT <- δB
 	δToid := δB.ΔByRoot[treeRoot]        // {} k -> δoid
@@ -1686,6 +1692,10 @@ func TestΔBTail(t *testing.T) {
 		"T/T/B0:a",
 		"T/B0:a",
 
+		// δtkeycov grows due to change in parent tree only
+		"T3/B1:a,2:b-B8:c,9:d",
+		"T7/B1:a,2:b-B8:c,9:d",
+
 
 //		"T/T/T/B1:a,2:b",
 //		"T/T/B1:a",