From 5b601f00b13996d5dacd5b7358ff6687341ac1dd Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander@bumpern.de>
Date: Wed, 18 Nov 2015 20:33:20 +0100
Subject: [PATCH] Add error checking

---
 repository/index.go      |  6 +++---
 repository/index_test.go |  2 +-
 repository/key.go        | 10 +++++-----
 repository/repository.go | 22 ++++++++++++++++------
 4 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/repository/index.go b/repository/index.go
index b75d69992..7bb4a273e 100644
--- a/repository/index.go
+++ b/repository/index.go
@@ -556,7 +556,7 @@ func DecodeOldIndex(rd io.Reader) (idx *Index, err error) {
 }
 
 // LoadIndexWithDecoder loads the index and decodes it with fn.
-func LoadIndexWithDecoder(repo *Repository, id string, fn func(io.Reader) (*Index, error)) (*Index, error) {
+func LoadIndexWithDecoder(repo *Repository, id string, fn func(io.Reader) (*Index, error)) (idx *Index, err error) {
 	debug.Log("LoadIndexWithDecoder", "Loading index %v", id[:8])
 
 	idxID, err := backend.ParseID(id)
@@ -568,9 +568,9 @@ func LoadIndexWithDecoder(repo *Repository, id string, fn func(io.Reader) (*Inde
 	if err != nil {
 		return nil, err
 	}
-	defer rd.Close()
+	defer closeOrErr(rd, &err)
 
-	idx, err := fn(rd)
+	idx, err = fn(rd)
 	if err != nil {
 		debug.Log("LoadIndexWithDecoder", "error while decoding index %v: %v", id, err)
 		return nil, err
diff --git a/repository/index_test.go b/repository/index_test.go
index 4a6f270fd..2e8a51e84 100644
--- a/repository/index_test.go
+++ b/repository/index_test.go
@@ -129,7 +129,7 @@ func TestIndexSerialize(t *testing.T) {
 		"index not final after encoding")
 
 	id := randomID()
-	idx.SetID(id)
+	OK(t, idx.SetID(id))
 	id2, err := idx.ID()
 	Assert(t, id2.Equal(id),
 		"wrong ID returned: want %v, got %v", id, id2)
diff --git a/repository/key.go b/repository/key.go
index 294c8561b..40e75f11d 100644
--- a/repository/key.go
+++ b/repository/key.go
@@ -112,23 +112,23 @@ func SearchKey(s *Repository, password string) (*Key, error) {
 }
 
 // LoadKey loads a key from the backend.
-func LoadKey(s *Repository, name string) (*Key, error) {
+func LoadKey(s *Repository, name string) (k *Key, err error) {
 	// extract data from repo
 	rd, err := s.be.Get(backend.Key, name)
 	if err != nil {
 		return nil, err
 	}
-	defer rd.Close()
+	defer closeOrErr(rd, &err)
 
 	// restore json
 	dec := json.NewDecoder(rd)
-	k := Key{}
-	err = dec.Decode(&k)
+	k = new(Key)
+	err = dec.Decode(k)
 	if err != nil {
 		return nil, err
 	}
 
-	return &k, nil
+	return k, nil
 }
 
 // AddKey adds a new key to an already existing repository.
diff --git a/repository/repository.go b/repository/repository.go
index 2aeceae54..03ba4ed59 100644
--- a/repository/repository.go
+++ b/repository/repository.go
@@ -143,19 +143,29 @@ func (r *Repository) LoadBlob(t pack.BlobType, id backend.ID, plaintextBuf []byt
 	return plaintextBuf, nil
 }
 
+// closeOrErr calls cl.Close() and sets err to the returned error value if
+// itself is not yet set.
+func closeOrErr(cl io.Closer, err *error) {
+	e := cl.Close()
+	if *err != nil {
+		return
+	}
+	*err = e
+}
+
 // LoadJSONUnpacked decrypts the data and afterwards calls json.Unmarshal on
 // the item.
-func (r *Repository) LoadJSONUnpacked(t backend.Type, id backend.ID, item interface{}) error {
+func (r *Repository) LoadJSONUnpacked(t backend.Type, id backend.ID, item interface{}) (err error) {
 	// load blob from backend
 	rd, err := r.be.Get(t, id.String())
 	if err != nil {
 		return err
 	}
-	defer rd.Close()
+	defer closeOrErr(rd, &err)
 
 	// decrypt
 	decryptRd, err := crypto.DecryptFrom(r.key, rd)
-	defer decryptRd.Close()
+	defer closeOrErr(decryptRd, &err)
 	if err != nil {
 		return err
 	}
@@ -172,7 +182,7 @@ func (r *Repository) LoadJSONUnpacked(t backend.Type, id backend.ID, item interf
 
 // LoadJSONPack calls LoadBlob() to load a blob from the backend, decrypt the
 // data and afterwards call json.Unmarshal on the item.
-func (r *Repository) LoadJSONPack(t pack.BlobType, id backend.ID, item interface{}) error {
+func (r *Repository) LoadJSONPack(t pack.BlobType, id backend.ID, item interface{}) (err error) {
 	// lookup pack
 	blob, err := r.idx.Lookup(id)
 	if err != nil {
@@ -184,11 +194,11 @@ func (r *Repository) LoadJSONPack(t pack.BlobType, id backend.ID, item interface
 	if err != nil {
 		return err
 	}
-	defer rd.Close()
+	defer closeOrErr(rd, &err)
 
 	// decrypt
 	decryptRd, err := crypto.DecryptFrom(r.key, rd)
-	defer decryptRd.Close()
+	defer closeOrErr(decryptRd, &err)
 	if err != nil {
 		return err
 	}