[FAB-6738] GetState in CouchDB fails to return database

For a while composer has created composite keys in a specific
format and this has worked fine. Since the introduction of a
change to the GetState protocol, GetState has not been returning
information.

Additional investigation showed that the error occurs due to a
bad URL generated when then key contains a colon ":"

Problem is resolved by encoding the path using url EscapedPath()
method instead of the String() method.

Note:  This commit also contains the fix from:
https://gerrit.hyperledger.org/r/#/c/13993 (FAB-6355)

Change-Id: I46a0a85728a36c0a8bd727ad28a75fc02b42206b
Signed-off-by: Chris Elder <[email protected]>

Author: Chris Elder

core/ledger/util/couchdb/couchdb.go

@@ -1395,13 +1395,22 @@ 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 {
+
+	logger.Debugf("Entering encodePathElement()  string=%s", str)
+
 	u := &url.URL{}
 	u.Path = str
-	encodedStr := u.String()
+	encodedStr := u.EscapedPath() // url encode using golang url path encoding rules
 	encodedStr = strings.Replace(encodedStr, "/", "%2F", -1)
+	encodedStr = strings.Replace(encodedStr, "+", "%2B", -1)
+
+	logger.Debugf("Exiting encodePathElement()  encodedStr=%s", encodedStr)
+
 	return encodedStr
 }
 

core/ledger/util/couchdb/couchdb_test.go

@@ -111,6 +111,25 @@ func TestDBBadConnectionDef(t *testing.T) {
 
 }
 
+func TestEncodePathElement(t *testing.T) {
+
+	encodedString := encodePathElement("testelement")
+	testutil.AssertEquals(t, encodedString, "testelement")
+
+	encodedString = encodePathElement("test element")
+	testutil.AssertEquals(t, encodedString, "test%20element")
+
+	encodedString = encodePathElement("/test element")
+	testutil.AssertEquals(t, encodedString, "%2Ftest%20element")
+
+	encodedString = encodePathElement("/test element:")
+	testutil.AssertEquals(t, encodedString, "%2Ftest%20element:")
+
+	encodedString = encodePathElement("/test+ element:")
+	testutil.AssertEquals(t, encodedString, "%2Ftest%2B%20element:")
+
+}
+
 func TestBadCouchDBInstance(t *testing.T) {
 
 	//TODO continue changes to return and removal of sprintf in followon changes