FAB-13612 Clarify error attempting to define seq 0

Although a user should never attempt to define a chaincode with sequence
0, if they do, the error returned is currently quite opaque.  This CR
adds an explicit check for this condition and returns a more useful
error message.

Change-Id: I868c813853d57de5306ac724f7e5a92bc2a4bc95
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

Author: Jason Yellick

core/chaincode/lifecycle/lifecycle.go

@@ -166,6 +166,10 @@ func (l *Lifecycle) DefineChaincodeForOrg(cd *ChaincodeDefinition, publicState R
 
 	requestedSequence := cd.Sequence
 
+	if currentSequence == requestedSequence && requestedSequence == 0 {
+		return errors.Errorf("requested sequence is 0, but first definable sequence number is 1")
+	}
+
 	if requestedSequence < currentSequence {
 		return errors.Errorf("currently defined sequence %d is larger than requested sequence %d", currentSequence, requestedSequence)
 	}

core/chaincode/lifecycle/lifecycle_test.go

@@ -201,6 +201,17 @@ var _ = Describe("Lifecycle", func() {
 			Expect(proto.Equal(committedDefinition.Collections, &cb.CollectionConfigPackage{})).To(BeTrue())
 		})
 
+		Context("when the current sequence is undefined and the requested sequence is 0", func() {
+			BeforeEach(func() {
+				fakePublicKVStore = map[string][]byte{}
+			})
+
+			It("returns an error", func() {
+				err := l.DefineChaincodeForOrg(&lifecycle.ChaincodeDefinition{}, fakePublicState, fakeOrgState)
+				Expect(err).To(MatchError("requested sequence is 0, but first definable sequence number is 1"))
+			})
+		})
+
 		Context("when the sequence number already has a definition", func() {
 			BeforeEach(func() {
 				fakePublicKVStore = map[string][]byte{}
@@ -362,7 +373,7 @@ var _ = Describe("Lifecycle", func() {
 		})
 	})
 
-	Describe("Define", func() {
+	Describe("DefineChaincode", func() {
 		var (
 			fakePublicState *mock.ReadWritableState
 			fakeOrgStates   []*mock.ReadWritableState