Allow CopyObject in pathStyle across federated instances (#8064)

Fixes #7976

cmd/generic-handlers.go

@@ -673,13 +673,18 @@ func (f bucketForwardingHandler) ServeHTTP(w http.ResponseWriter, r *http.Reques
 				bucket, _ = urlPath2BucketObjectName(r.URL.Path)
 			}
 		}
-		if bucket != "" {
+		if bucket == "" {
+			f.handler.ServeHTTP(w, r)
+			return
+		}
 		sr, err := globalDNSConfig.Get(bucket)
 		if err != nil {
 			if err == dns.ErrNoEntriesFound {
-					writeErrorResponse(context.Background(), w, errorCodes.ToAPIErr(ErrNoSuchBucket), r.URL, guessIsBrowserReq(r))
+				writeErrorResponse(context.Background(), w, errorCodes.ToAPIErr(ErrNoSuchBucket),
+					r.URL, guessIsBrowserReq(r))
 			} else {
-					writeErrorResponse(context.Background(), w, toAPIError(context.Background(), err), r.URL, guessIsBrowserReq(r))
+				writeErrorResponse(context.Background(), w, toAPIError(context.Background(), err),
+					r.URL, guessIsBrowserReq(r))
 			}
 			return
 		}
@@ -692,8 +697,6 @@ func (f bucketForwardingHandler) ServeHTTP(w http.ResponseWriter, r *http.Reques
 			f.fwd.ServeHTTP(w, r)
 			return
 		}
-		}
-		f.handler.ServeHTTP(w, r)
 		return
 	}
 
@@ -715,10 +718,13 @@ func (f bucketForwardingHandler) ServeHTTP(w http.ResponseWriter, r *http.Reques
 	// CopyObject requests should be handled at current endpoint as path style
 	// requests have target bucket and object in URI and source details are in
 	// header fields
-	if r.Method == http.MethodPut && r.Header.Get("X-Amz-Copy-Source") != "" {
+	if r.Method == http.MethodPut && r.Header.Get(xhttp.AmzCopySource) != "" {
+		bucket, object = urlPath2BucketObjectName(r.Header.Get(xhttp.AmzCopySource))
+		if bucket == "" || object == "" {
 			f.handler.ServeHTTP(w, r)
 			return
 		}
+	}
 	sr, err := globalDNSConfig.Get(bucket)
 	if err != nil {
 		if err == dns.ErrNoEntriesFound {

cmd/object-handlers.go

@@ -1063,7 +1063,7 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 	r.Body = &detectDisconnect{r.Body, r.Context().Done()}
 
 	// X-Amz-Copy-Source shouldn't be set for this call.
-	if _, ok := r.Header["X-Amz-Copy-Source"]; ok {
+	if _, ok := r.Header[xhttp.AmzCopySource]; ok {
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidCopySource), r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -1086,7 +1086,7 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 	size := r.ContentLength
 	rAuthType := getRequestAuthType(r)
 	if rAuthType == authTypeStreamingSigned {
-		if sizeStr, ok := r.Header["X-Amz-Decoded-Content-Length"]; ok {
+		if sizeStr, ok := r.Header[xhttp.AmzDecodedContentLength]; ok {
 			if sizeStr[0] == "" {
 				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrMissingContentLength), r.URL, guessIsBrowserReq(r))
 				return