From 7a66a7dc9ffb28a6dfccf692b78968ce44235563 Mon Sep 17 00:00:00 2001
From: Tommi Virtanen <tv@eagain.net>
Date: Mon, 8 Jun 2015 21:42:04 -0700
Subject: [PATCH] pin: Do not accidentally delete indirect pins on Flush

License: MIT
Signed-off-by: Jeromy <jeromyj@gmail.com>
---
 pin/pin_test.go | 21 +++++++++++++++++++++
 pin/set.go      | 11 +++++++++++
 2 files changed, 32 insertions(+)

diff --git a/pin/pin_test.go b/pin/pin_test.go
index d3947254d..e96adb292 100644
--- a/pin/pin_test.go
+++ b/pin/pin_test.go
@@ -192,6 +192,27 @@ func TestDuplicateSemantics(t *testing.T) {
 	}
 }
 
+func TestFlush(t *testing.T) {
+	dstore := dssync.MutexWrap(ds.NewMapDatastore())
+	bstore := blockstore.NewBlockstore(dstore)
+	bserv, err := bs.New(bstore, offline.Exchange(bstore))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dserv := mdag.NewDAGService(bserv)
+	p := NewPinner(dstore, dserv)
+	_, k := randNode()
+
+	p.PinWithMode(k, Indirect)
+	if err := p.Flush(); err != nil {
+		t.Fatal(err)
+	}
+	if !p.IsPinned(k) {
+		t.Fatal("expected key to still be pinned")
+	}
+}
+
 func TestPinRecursiveFail(t *testing.T) {
 	ctx := context.Background()
 	dstore := dssync.MutexWrap(ds.NewMapDatastore())
diff --git a/pin/set.go b/pin/set.go
index 4b6edc2ed..71851af6e 100644
--- a/pin/set.go
+++ b/pin/set.go
@@ -314,7 +314,18 @@ func storeSet(ctx context.Context, dag merkledag.DAGService, keys []key.Key, int
 	return n, nil
 }
 
+func copyRefcounts(orig map[key.Key]uint64) map[key.Key]uint64 {
+	r := make(map[key.Key]uint64, len(orig))
+	for k, v := range orig {
+		r[k] = v
+	}
+	return r
+}
+
 func storeMultiset(ctx context.Context, dag merkledag.DAGService, refcounts map[key.Key]uint64, internalKeys keyObserver) (*merkledag.Node, error) {
+	// make a working copy of the refcounts
+	refcounts = copyRefcounts(refcounts)
+
 	iter := func() (k key.Key, data []byte, ok bool) {
 		// Every call of this function returns the next refcount item.
 		//