cmd/swarm, swarm/api: bzzr improve + networkid prio

fixes #3444
fixes #3494
networkid override

Added comments to explain why test against 0 appears twice

* Command line overrides saved config, saved config overrides system default

---

fixes #3476
bzzr get with path

Finally a hopefully clean commit for this PR
Added check for empty path to avoid SIGSEGV in path parser and resolver
Added requested tests for empty path and non-existing manifest.
However signature for StartHTTPServer had changed.
Now it's hacked as so:

	StartHttpServer(api.API, &Server{Addr: "127.0.0.1:8504", CorsString: ""})

* Parse url before resolve when path and ENS is supplied, example
* swarm/api/http proxy server test for retrieval of subpath through get
* Removed nil entry assignment on subtrie leaf in recursive key retrieval
* Cleaned up path-or-no-path condition in proxy server get handler
* swarm: processed with gofmt refers to lash/go-ethereum@90daa7a
* swarm: Added public access method Parse alias to parse
* swarm: processed with gofmt References nolash/go-ethereum@2ec3fd7
* Rename parse to Parse, removed alias

1 files changed, 14 insertions, 0 deletions

diff --git a/swarm/api/config.go b/swarm/api/config.go
index b4c6e3d4a..23a855500 100644
--- a/swarm/api/config.go
+++ b/swarm/api/config.go
@@ -85,10 +85,17 @@ func NewConfig(path string, contract common.Address, prvKey *ecdsa.PrivateKey, n
 		NetworkId:     networkId,
 	}
 	data, err = ioutil.ReadFile(confpath)
+
+	// if not set in function param, then set default for swarm network, will be overwritten by config file if present
+	if networkId == 0 {
+		self.NetworkId = network.NetworkId
+	}
+
 	if err != nil {
 		if !os.IsNotExist(err) {
 			return
 		}
+
 		// file does not exist
 		// write out config file
 		err = self.Save()
@@ -97,6 +104,7 @@ func NewConfig(path string, contract common.Address, prvKey *ecdsa.PrivateKey, n
 		}
 		return
 	}
+
 	// file exists, deserialise
 	err = json.Unmarshal(data, self)
 	if err != nil {
@@ -109,6 +117,12 @@ func NewConfig(path string, contract common.Address, prvKey *ecdsa.PrivateKey, n
 	if keyhex != self.BzzKey {
 		return nil, fmt.Errorf("bzz key does not match the one in the config file %v != %v", keyhex, self.BzzKey)
 	}
+
+	// if set in function param, replace id set from config file
+	if networkId != 0 {
+		self.NetworkId = networkId
+	}
+
 	self.Swap.SetKey(prvKey)
 
 	if (self.EnsRoot == common.Address{}) {