From f77027e6b7f7bef853f6b89d7e1f126e9c131195 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Thu, 12 Sep 2019 11:12:19 +0100
Subject: [PATCH] fs/accounting: Fix "file already closed" on transfer retries

This was caused by the recent reworking of the accounting interface.
The Transfer object was recycling the Accounting object without
resetting the stream.

See: https://forum.rclone.org/t/error-file-already-closed/11469/
See: https://forum.rclone.org/t/rclone-b2-sync-post-error-method-not-supported/11718/
---
 fs/accounting/accounting.go | 8 ++++++--
 fs/accounting/transfer.go   | 2 ++
 fs/operations/operations.go | 1 +
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/accounting/accounting.go b/fs/accounting/accounting.go
index 81a1b56f5..b2544df72 100644
--- a/fs/accounting/accounting.go
+++ b/fs/accounting/accounting.go
@@ -118,11 +118,15 @@ func (acc *Account) StopBuffering() {
 // async buffer (if any) and re-adding it
 func (acc *Account) UpdateReader(in io.ReadCloser) {
 	acc.mu.Lock()
-	acc.StopBuffering()
+	if acc.withBuf {
+		acc.StopBuffering()
+	}
 	acc.in = in
 	acc.close = in
 	acc.origIn = in
-	acc.WithBuffer()
+	if acc.withBuf {
+		acc.WithBuffer()
+	}
 	acc.mu.Unlock()
 }
 
diff --git a/fs/accounting/transfer.go b/fs/accounting/transfer.go
index 0d968661b..a1ab8d023 100644
--- a/fs/accounting/transfer.go
+++ b/fs/accounting/transfer.go
@@ -117,6 +117,8 @@ func (tr *Transfer) Account(in io.ReadCloser) *Account {
 	tr.mu.Lock()
 	if tr.acc == nil {
 		tr.acc = newAccountSizeName(tr.stats, in, tr.size, tr.remote)
+	} else {
+		tr.acc.UpdateReader(in)
 	}
 	tr.mu.Unlock()
 	return tr.acc
diff --git a/fs/operations/operations.go b/fs/operations/operations.go
index 14d01519a..524bca9c9 100644
--- a/fs/operations/operations.go
+++ b/fs/operations/operations.go
@@ -341,6 +341,7 @@ func Copy(ctx context.Context, f fs.Fs, dst fs.Object, remote string, src fs.Obj
 						} else {
 							actionTaken = "Copied (Rcat, new)"
 						}
+						// NB Rcat closes in0
 						dst, err = Rcat(ctx, f, remote, in0, src.ModTime(ctx))
 						newDst = dst
 					} else {