[FAB-6355] Fix GetPrivateData() error on CouchDB

The problem was that the retrieve of the public
hash from couch state db fails due to a URL
encoding issue of a plus sign in the hashed key.

Keys were already URL encoded using golang URL
encoding, but the encoding skips plus signs in
the path component.  CouchDB unencodes the plus
sign as a space.

The fix is to explicitly URL encode plus character
when interacting with CouchDB.

Also add unit test to verify the fix and test
all other URL special characters.

Also clarified the error message received when
private version does not match public hash.

Change-Id: I9b99d3446542e9eae0196158270205d3ea09db9f
Signed-off-by: David Enyeart <enyeart@us.ibm.com>

core/ledger/kvledger/txmgmt/txmgr/lockbasedtxmgr/helper.go

@@ -119,7 +119,7 @@ func (h *queryHelper) getPrivateData(ns, coll, key string) ([]byte, error) {
 	}
 	if !version.AreSame(hashVersion, ver) {
 		return nil, &txmgr.ErrPvtdataNotAvailable{Msg: fmt.Sprintf(
-			"The available copy of the private data is not latest. The latest version = %#v, available version = %#v",
+			"Private data matching public hash version is not available. Public hash version = %#v, Private data version = %#v",
 			hashVersion, ver)}
 	}
 	if h.rwsetBuilder != nil {

core/ledger/util/couchdb/couchdb.go

@@ -1407,13 +1407,16 @@ func IsJSON(s string) bool {
 	return json.Unmarshal([]byte(s), &js) == nil
 }
 
-// encodePathElement uses Golang for encoding and in addition, replaces a '/' by %2F.
-// Otherwise, in the regular encoding, a '/' is treated as a path separator in the url
+// encodePathElement uses Golang for url path encoding, additionally:
+// '/' is replaced by %2F, otherwise path encoding will treat as path separator and ignore it
+// '+' is replaced by %2B, otherwise path encoding will ignore it, while CouchDB will unencode the plus as a space
+// Note that all other URL special characters have been tested successfully without need for special handling
 func encodePathElement(str string) string {
 	u := &url.URL{}
 	u.Path = str
-	encodedStr := u.String()
+	encodedStr := u.String() // url encode using golang url path encoding rules
 	encodedStr = strings.Replace(encodedStr, "/", "%2F", -1)
+	encodedStr = strings.Replace(encodedStr, "+", "%2B", -1)
 	return encodedStr
 }
 

core/ledger/util/couchdb/couchdb_test.go

@@ -1130,6 +1130,7 @@ func TestBatchBatchOperations(t *testing.T) {
 		byteJSON03 := []byte(`{"_id":"marble03","asset_name":"marble03","color":"green","size":"3","owner":"jerry"}`)
 		byteJSON04 := []byte(`{"_id":"marble04","asset_name":"marble04","color":"purple","size":"4","owner":"tom"}`)
 		byteJSON05 := []byte(`{"_id":"marble05","asset_name":"marble05","color":"blue","size":"5","owner":"jerry"}`)
+		byteJSON06 := []byte(`{"_id":"marble06#$&'()*+,/:;=?@[]","asset_name":"marble06#$&'()*+,/:;=?@[]","color":"blue","size":"6","owner":"jerry"}`)
 
 		attachment1 := &AttachmentInfo{}
 		attachment1.AttachmentBytes = []byte(`marble01 - test attachment`)
@@ -1166,6 +1167,13 @@ func TestBatchBatchOperations(t *testing.T) {
 		attachments5 := []*AttachmentInfo{}
 		attachments5 = append(attachments5, attachment5)
 
+		attachment6 := &AttachmentInfo{}
+		attachment6.AttachmentBytes = []byte(`marble06#$&'()*+,/:;=?@[] - test attachment`)
+		attachment6.ContentType = "application/octet-stream"
+		attachment6.Name = "data"
+		attachments6 := []*AttachmentInfo{}
+		attachments6 = append(attachments6, attachment6)
+
 		database := "testbatch"
 		err := cleanup(database)
 		testutil.AssertNoError(t, err, fmt.Sprintf("Error when trying to cleanup  Error: %s", err))
@@ -1188,12 +1196,14 @@ func TestBatchBatchOperations(t *testing.T) {
 		value3 := &CouchDoc{JSONValue: byteJSON03, Attachments: attachments3}
 		value4 := &CouchDoc{JSONValue: byteJSON04, Attachments: attachments4}
 		value5 := &CouchDoc{JSONValue: byteJSON05, Attachments: attachments5}
+		value6 := &CouchDoc{JSONValue: byteJSON06, Attachments: attachments6}
 
 		batchUpdateDocs = append(batchUpdateDocs, value1)
 		batchUpdateDocs = append(batchUpdateDocs, value2)
 		batchUpdateDocs = append(batchUpdateDocs, value3)
 		batchUpdateDocs = append(batchUpdateDocs, value4)
 		batchUpdateDocs = append(batchUpdateDocs, value5)
+		batchUpdateDocs = append(batchUpdateDocs, value6)
 
 		batchUpdateResp, err := db.BatchUpdateDocuments(batchUpdateDocs)
 		testutil.AssertNoError(t, err, fmt.Sprintf("Error when attempting to update a batch of documents"))
@@ -1214,6 +1224,18 @@ func TestBatchBatchOperations(t *testing.T) {
 		//Verify the owner retrieved matches
 		testutil.AssertEquals(t, assetResp.Owner, "jerry")
 
+		//----------------------------------------------
+		// Test Retrieve JSON using ID with URL special characters,
+		// this will confirm that batch document IDs and URL IDs are consistent, even if they include special characters
+		dbGetResp, _, geterr = db.ReadDoc("marble06#$&'()*+,/:;=?@[]")
+		testutil.AssertNoError(t, geterr, fmt.Sprintf("Error when attempting read a document"))
+
+		assetResp = &Asset{}
+		geterr = json.Unmarshal(dbGetResp.JSONValue, &assetResp)
+		testutil.AssertNoError(t, geterr, fmt.Sprintf("Error when trying to retrieve a document"))
+		//Verify the owner retrieved matches
+		testutil.AssertEquals(t, assetResp.Owner, "jerry")
+
 		//----------------------------------------------
 		//Test retrieve binary
 		dbGetResp, _, geterr = db.ReadDoc("marble03")