X rebuild: tests: Move ΔBtail.Clone test out of hot inner loop into separate test

73s -> 68s

wcfs/internal/xbtree/δbtail_test.go

@@ -1119,11 +1119,6 @@ func xverifyΔBTail_rebuild(t *testing.T, db *zodb.DB, treeRoot zodb.Oid, t0, t1
 								// after rebuild
 								/* trackSet=*/ t2.xkv.trackSet(keys12R2),
 								/*vδT=*/ δkv1_k12R2, δkv2_k12R2)
-
-							// XXX move vvv to separate test (out of this inner loop)
-							// ΔBtail.Clone had bug that aliased klon data to orig
-							assertΔTtail(t, "BUG: after clone check", δbtail, t2, treeRoot, xat,
-								/*vδT=*/ δkv1_k1R2, δkv2_k1R2)
 						//})
 					}
 				})
@@ -1395,7 +1390,7 @@ func ΔBTest(xtest interface{}) ΔBTestEntry {
 //
 // It combines TreeSrv and client side access to ZODB with committed trees. XXX
 //
-// Create it with tTreeEnv().
+// Create it with tNewTreeEnv().
 type tTreeEnv struct {
 	*testing.T
 
@@ -1455,7 +1450,7 @@ func tNewTreeEnv(t *testing.T) *tTreeEnv {
 		tree:       "T/B:",	// treegen.py creates the tree as initially empty
 		prev:       nil,
 		at:         head,
-		xkv:        XGetTree(tt.db, head, tt.treeSrv.treeRoot),
+		xkv:        XGetTree(tt.db, head, tt.Root()),
 		blkDataTab: xGetBlkDataTab(tt.db, head),
 		δZ:         nil,
 		δxkv:       nil,
@@ -1474,6 +1469,10 @@ func (_ *tZODBCacheEverything) PCacheClassify(_ zodb.IPersistent) zodb.PCachePol
 	return zodb.PCachePinObject | zodb.PCacheKeepState
 }
 
+// Root returns OID of root tree node.
+func (t *tTreeEnv) Root() zodb.Oid {
+	return t.treeSrv.treeRoot
+}
 
 // Head returns most-recently committed tree.
 func (t *tTreeEnv) Head() *tTreeCommit {
@@ -1506,9 +1505,9 @@ func (t *tTreeEnv) CommitTree(tree string) *tTreeCommit {
 	// if the tree does not exist yet - report its structure as empty
 	var xkv RBucketSet
 	if tree != DEL {
-		xkv = XGetTree(t.db, δZ.Tid, t.treeSrv.treeRoot)
+		xkv = XGetTree(t.db, δZ.Tid, t.Root())
 	} else {
-		// empty tree with real treeSrv.treeRoot as oid even though the tree is
+		// empty tree with real treeRoot as oid even though the tree is
 		// deleted.  Having real oid in the root tests that after deletion,
 		// root of the tree stays in the tracking set. We need root to stay
 		// in trackSet because e.g. in
@@ -1522,7 +1521,7 @@ func (t *tTreeEnv) CommitTree(tree string) *tTreeCommit {
 			&RBucket{
 				oid:    zodb.InvalidOid,
 				parent: &RTree{
-					oid:    t.treeSrv.treeRoot, // NOTE oid is not InvalidOid
+					oid:    t.Root(), // NOTE oid is not InvalidOid
 					parent: nil,
 				},
 				lo:     KeyMin,
@@ -1634,11 +1633,11 @@ func testΔBTail(t_ *testing.T, testq chan ΔBTestEntry) {
 		}
 
 		// ΔBTail.Update
-		xverifyΔBTail_Update(t.T, subj, t.db, t.treeSrv.treeRoot, t1,t2)
+		xverifyΔBTail_Update(t.T, subj, t.db, t.Root(), t1,t2)
 
 		// ΔBTail.rebuild
 		if t0 != nil {
-			xverifyΔBTail_rebuild(t.T, t.db, t.treeSrv.treeRoot, t0,t1,t2)
+			xverifyΔBTail_rebuild(t.T, t.db, t.Root(), t0,t1,t2)
 		}
 
 		t0, t1 = t1, t2
@@ -2040,6 +2039,39 @@ func TestΔBTailAllStructs(t *testing.T) {
 
 // ---- misc ----
 
+func TestΔBtailClone(t_ *testing.T) {
+	// ΔBtail.Clone had bug that aliased klon data to orig
+	t := tNewTreeEnv(t_)
+	X := exc.Raiseif
+
+	t0 := t.CommitTree("T2/B1:a-B2:b")
+	t1 := t.CommitTree("T2/B1:c-B2:d")
+	δbtail := NewΔBtail(t0.at, t.db)
+	_, err := δbtail.Update(t1.δZ); X(err)
+	_2 := SetKey{}; _2.Add(2)
+	xtrackKeys(δbtail, t1, _2)
+	err = δbtail.rebuildAll(); X(err)
+
+	xat := map[zodb.Tid]string{
+		t0.at: "at0",
+		t1.at: "at1",
+	}
+
+	δkv1_1 := map[Key]Δstring{2:{"b","d"}}
+	assertΔTtail(t.T, "orig @at1", δbtail, t1, t.Root(), xat, δkv1_1)
+	δbklon := δbtail.Clone()
+	assertΔTtail(t.T, "klon @at1", δbklon, t1, t.Root(), xat, δkv1_1)
+
+	t2 := t.CommitTree("T/B1:b,2:a")
+	_, err = δbtail.Update(t2.δZ); X(err)
+	xat[t2.at] = "at2"
+
+	δkv1_2 := map[Key]Δstring{1:{"a","c"}, 2:{"b","d"}}
+	δkv2_2 := map[Key]Δstring{1:{"c","b"}, 2:{"d","a"}}
+	assertΔTtail(t.T, "orig @at2", δbtail, t2, t.Root(), xat, δkv1_2, δkv2_2)
+	assertΔTtail(t.T, "klon @at1 after orig @at->@at2", δbklon, t1, t.Root(), xat, δkv1_1)
+}
+
 
 // IntSets generates all sets of integers in range [0,N)
 func IntSets(N int) chan []int {