Fix sync bug when in TypeA and TypeB sync style source doesn't exist

cmd-sync.go

@@ -23,6 +23,7 @@ import (
 	"os"
 	"os/signal"
 	"runtime"
+	"strings"
 	"sync"
 
 	"github.com/minio/cli"
@@ -71,9 +72,13 @@ EXAMPLES:
 
 // doSyncSession - Sync an object to multiple destination
 func doSyncSession(sURLs syncURLs, bar *barSend, syncQueue chan bool, ssCh chan syncSession, wg *sync.WaitGroup, s *sessionV1) {
+	// waitgroup reply deferred until this function returns
 	defer wg.Done()
+
+	// hold lock for map updates inside session
 	s.Lock.Lock()
 	defer s.Lock.Unlock()
+
 	if !globalQuietFlag {
 		bar.SetCaption(sURLs.SourceContent.Name + ": ")
 	}
@@ -105,6 +110,10 @@ func doSyncSession(sURLs syncURLs, bar *barSend, syncQueue chan bool, ssCh chan
 	var newReader io.Reader
 	switch globalQuietFlag {
 	case true:
+		console.Infos(SyncMessage{
+			Source: sURLs.SourceContent.Name,
+			Target: strings.Join(targetURLs, " "),
+		})
 		newReader = yielder.NewReader(reader)
 	default:
 		// set up progress

cp-url.go

@@ -53,6 +53,13 @@ type cpURLs struct {
 	Error         error
 }
 
+func (c cpURLs) IsEmpty() bool {
+	if c.SourceContent == nil && c.TargetContent == nil {
+		return true
+	}
+	return false
+}
+
 type cpURLsType uint8
 
 const (

print-structs.go

@@ -74,6 +74,7 @@ func (i InfoMessage) String() string {
 	return i.Message
 }
 
+// CopyMessage container for file copy messages
 type CopyMessage struct {
 	Message string `json:"message"`
 	Source  string `json:"source"`
@@ -83,3 +84,10 @@ type CopyMessage struct {
 func (c CopyMessage) String() string {
 	return fmt.Sprintf("‘%s’ -> ‘%s’", c.Source, c.Target)
 }
+
+// SyncMessage container for file sync messages, inherits CopyMessage
+type SyncMessage CopyMessage
+
+func (s SyncMessage) String() string {
+	return fmt.Sprintf("‘%s’ -> ‘%s’", s.Source, s.Target)
+}

sync-url.go

@@ -52,6 +52,22 @@ type syncURLs struct {
 	Error          error
 }
 
+func (s syncURLs) IsEmpty() bool {
+	empty := false
+	if s.SourceContent == nil {
+		empty = true
+		if s.TargetContents == nil {
+			empty = true
+			return empty
+		}
+		if len(s.TargetContents) > 0 && s.TargetContents[0] == nil {
+			empty = true
+			return empty
+		}
+	}
+	return empty
+}
+
 type syncURLsType cpURLsType
 
 // guessSyncURLType guesses the type of URL. This approach all allows prepareURL
@@ -91,7 +107,9 @@ func prepareSyncURLsTypeA(sourceURL string, targetURLs []string) <-chan syncURLs
 			sURLs.SourceContent = cURLs.SourceContent
 			sURLs.TargetContents = append(sURLs.TargetContents, cURLs.TargetContent)
 		}
-		syncURLsCh <- sURLs
+		if !sURLs.IsEmpty() {
+			syncURLsCh <- sURLs
+		}
 	}()
 	return syncURLsCh
 }
@@ -113,7 +131,9 @@ func prepareSyncURLsTypeB(sourceURL string, targetURLs []string) <-chan syncURLs
 			sURLs.SourceContent = cURLs.SourceContent
 			sURLs.TargetContents = append(sURLs.TargetContents, cURLs.TargetContent)
 		}
-		syncURLsCh <- sURLs
+		if !sURLs.IsEmpty() {
+			syncURLsCh <- sURLs
+		}
 	}()
 	return syncURLsCh
 }