.

wcfs/internal/xbtree/δbtail.go

@@ -371,8 +371,6 @@ func (δTtail *_ΔTtail) rebuild(root zodb.Oid, δZtail *zodb.ΔTail, db *zodb.D
 		for i := len(vδZ)-1; i>=0; i-- {
 			δZ := vδZ[i]
 
-			// XXX dup wrt Update?
-
 			var atPrev zodb.Tid
 			if i > 0 {
 				atPrev = vδZ[i-1].Rev
@@ -437,6 +435,8 @@ func (δTtail *_ΔTtail) rebuild1(atPrev zodb.Tid, δZ zodb.ΔRevEntry, trackNew
 		debugfΔBtail("\n\n")
 	}()
 
+	// NOTE: keep vvv in sync with ΔBtail._Update1
+
 	δZTC, δtopsByRoot := δZConnectTracked(δZ.Changev, trackNew)
 
 	// skip opening DB connections if there is no change to this tree
@@ -617,7 +617,7 @@ type _ΔBUpdate1 struct {
 	ByRoot map[zodb.Oid]*_ΔTUpdate1
 }
 type _ΔTUpdate1 struct {
-	δtkeycov1 *blib.RangedKeySet   // {} root -> δtrackedKeys after first treediff (always grow)
+	δtkeycov1 *blib.RangedKeySet // {} root -> δtrackedKeys after first treediff (always grow)
 }
 func (δBtail *ΔBtail) _Update1(δZ *zodb.EventCommit) (δB1 _ΔBUpdate1, err error) {
 	headOld := δBtail.Head()
@@ -638,10 +638,10 @@ func (δBtail *ΔBtail) _Update1(δZ *zodb.EventCommit) (δB1 _ΔBUpdate1, err e
 		return δB1, err
 	}
 
-	// XXX dup wrt rebuild?
-
 	δBtail.δZtail.Append(δZ.Tid, δZ.Changev)
 
+	// NOTE: keep vvv in sync with ΔTtail.rebuild1
+
 	δZTC, δtopsByRoot := δZConnectTracked(δZ.Changev, δBtail.trackSet)
 
 	// skip opening DB connections if there is no change to any tree node