.

wcfs/internal/zdata/δftail_test.go

@@ -156,20 +156,19 @@ func TestΔFtail(t_ *testing.T) {
 			}
 		}
 
-		if len(δblk) == 0 {
-			t.Fatal("BUG: prepared δblk = ø")
-		}
-
 		// commit updated blkTab + dataTab
 		tdTxt := fmt.Sprintf("t%s D%s", xbtreetest.KVTxt(blkTab), dataTabTxt(dataTab))
 		commit := t.CommitTree(tdTxt)
 
-		δfok := &ΔFile{
-			Rev:    commit.At,
-			Blocks: δblk,
-			Size:   true/*XXX*/,
+		var δfok *ΔFile
+		if len(δblk) != 0 {
+			δfok = &ΔFile{
+				Rev:    commit.At,
+				Blocks: δblk,
+				Size:   true/*XXX*/,
+			}
+			vδf = append(vδf, δfok)
 		}
-		vδf = append(vδf, δfok)
 
 		fmt.Printf("@%s  δT: %v   δD: %s\n", commit.At, test.δblkTab, test.δdataTab)
 		fmt.Printf("@%s  %s\n", commit.At, commit.Tree)
@@ -177,20 +176,27 @@ func TestΔFtail(t_ *testing.T) {
 		// update δftail
 		δF, err := δftail.Update(commit.ΔZ);  X(err)
 
-		// assert δF points to the file
-		if δF.Rev != δfok.Rev {
-			t.Errorf("wrong δF.Rev: have %s  ; want %s", δF.Rev, δfok.Rev)
+		// assert δF points to the file if δfok != ø
+		if δF.Rev != commit.At {
+			t.Errorf("wrong δF.Rev: have %s  ; want %s", δF.Rev, commit.At)
 		}
 		δfiles := setOid{}
 		for δfile := range δF.ByFile {
 			δfiles.Add(δfile)
 		}
-		δfilesOK := setOid{}; δfilesOK.Add(zfile.POid())
+		δfilesOK := setOid{}
+		if δfok != nil {
+			δfilesOK.Add(zfile.POid())
+		}
 		if !δfiles.Equal(δfilesOK) {
 			t.Errorf("wrong δF.ByFile:\nhave keys: %s\nwant keys: %s", δfiles, δfilesOK)
 			continue
 		}
 
+		if δfok == nil {
+			continue
+		}
+
 		// verify δf
 		δf := δF.ByFile[zfile.POid()]
 		if !reflect.DeepEqual(δf, δfok) {