Merge pull request #18680 from aaronlehmann/duplicate-pull-complete-message

Avoid outputting last progress item twice

distribution/xfer/transfer.go

@@ -124,7 +124,6 @@ func (t *transfer) Broadcast(masterProgressChan <-chan progress.Progress) {
 				default:
 				}
 			}
-
 		} else {
 			t.broadcastDone = true
 		}
@@ -159,18 +158,23 @@ func (t *transfer) Watch(progressOutput progress.Output) *Watcher {
 		defer func() {
 			close(w.running)
 		}()
-		done := false
+		var (
+			done           bool
+			lastWritten    progress.Progress
+			hasLastWritten bool
+		)
 		for {
 			t.mu.Lock()
 			hasLastProgress := t.hasLastProgress
 			lastProgress := t.lastProgress
 			t.mu.Unlock()
 
-			// This might write the last progress item a
-			// second time (since channel closure also gets
-			// us here), but that's fine.
-			if hasLastProgress {
+			// Make sure we don't write the last progress item
+			// twice.
+			if hasLastProgress && (!done || !hasLastWritten || lastProgress != lastWritten) {
 				progressOutput.WriteProgress(lastProgress)
+				lastWritten = lastProgress
+				hasLastWritten = true
 			}
 
 			if done {

distribution/xfer/transfer_test.go

@@ -41,15 +41,6 @@ func TestTransfer(t *testing.T) {
 				if p.Current != 0 {
 					t.Fatalf("got unexpected progress value: %d (expected 0)", p.Current)
 				}
-			} else if p.Current == 10 {
-				// Special case: last progress output may be
-				// repeated because the transfer finishing
-				// causes the latest progress output to be
-				// written to the channel (in case the watcher
-				// missed it).
-				if p.Current != 9 && p.Current != 10 {
-					t.Fatalf("got unexpected progress value: %d (expected %d)", p.Current, val+1)
-				}
 			} else if p.Current != val+1 {
 				t.Fatalf("got unexpected progress value: %d (expected %d)", p.Current, val+1)
 			}