Use default path if none given when rebuilding chain.

eth/main.cpp

@@ -121,7 +121,7 @@ void help()
 		<< "    --json-rpc-port <n>  Specify JSON-RPC server port (implies '-j', default: " << SensibleHttpPort << ")." << endl
 #endif
 		<< "    -K,--kill  First kill the blockchain." << endl
-		<< "    -R,--rebuild  First rebuild the blockchain from the existing database." << endl
+		<< "    -R,--rebuild  Rebuild the blockchain from the existing database." << endl
 		<< "    -s,--secret <secretkeyhex>  Set the secret key for use with send command (default: auto)." << endl
 		<< "    -S,--session-secret <secretkeyhex>  Set the secret key for use with send command, for this session only." << endl
 		<< "Client transacting:" << endl
@@ -598,7 +598,7 @@ int main(int argc, char** argv)
 			}
 		else if (arg == "-K" || arg == "--kill-blockchain" || arg == "--kill")
 			killChain = WithExisting::Kill;
-		else if (arg == "-B" || arg == "--rebuild")
+		else if (arg == "-R" || arg == "--rebuild")
 			killChain = WithExisting::Verify;
 		else if ((arg == "-c" || arg == "--client-name") && i + 1 < argc)
 		{

libethereum/BlockChain.cpp

@@ -185,6 +185,8 @@ void BlockChain::close()
 
 void BlockChain::rebuild(std::string const& _path, std::function<void(unsigned, unsigned)> const& _progress)
 {
+	std::string path = _path.empty() ? Defaults::get()->m_dbPath : _path;
+
 #if ETH_PROFILING_GPERF
 	ProfilerStart("BlockChain_rebuild.log");
 #endif
@@ -195,16 +197,16 @@ void BlockChain::rebuild(std::string const& _path, std::function<void(unsigned,
 	// Keep extras DB around, but under a temp name
 	delete m_extrasDB;
 	m_extrasDB = nullptr;
-	IGNORE_EXCEPTIONS(boost::filesystem::remove_all(_path + "/details.old"));
-	boost::filesystem::rename(_path + "/details", _path + "/details.old");
+	IGNORE_EXCEPTIONS(boost::filesystem::remove_all(path + "/details.old"));
+	boost::filesystem::rename(path + "/details", path + "/details.old");
 	ldb::DB* oldExtrasDB;
 	ldb::Options o;
 	o.create_if_missing = true;
-	ldb::DB::Open(o, _path + "/details.old", &oldExtrasDB);
-	ldb::DB::Open(o, _path + "/details", &m_extrasDB);
+	ldb::DB::Open(o, path + "/details.old", &oldExtrasDB);
+	ldb::DB::Open(o, path + "/details", &m_extrasDB);
 
 	// Open a fresh state DB
-	State s(State::openDB(_path, WithExisting::Kill), BaseState::CanonGenesis);
+	State s(State::openDB(path, WithExisting::Kill), BaseState::CanonGenesis);
 
 	// Clear all memos ready for replay.
 	m_details.clear();
@@ -255,7 +257,7 @@ void BlockChain::rebuild(std::string const& _path, std::function<void(unsigned,
 #endif
 
 	delete oldExtrasDB;
-	boost::filesystem::remove_all(_path + "/details.old");
+	boost::filesystem::remove_all(path + "/details.old");
 }
 
 template <class T, class V>