X Fix PartTab(ø).Operational

It was erroneously giving true, which if Client.Load ran earlier than
talkMaster->init could result in:

F0906 12:34:16.353097    7933 zsha1.go:32] zsha1: client: load <03c1e49367e07912:0000000000000000: internal inconsistency: cluster is operational, but no storages alive for oid 0000000000000000

go/neo/parttab.go

@@ -182,6 +182,11 @@ func MakePartTab(np int, nodev []*Node) *PartitionTable {
 //
 // XXX or keep not only NodeUUID in Cell - add *Node ?
 func (pt *PartitionTable) OperationalWith(nt *NodeTable) bool {
+	// empty partition table is never operational
+	if len(pt.tab) == 0 {
+		return false
+	}
+
 	for _, ptEntry := range pt.tab {
 		if len(ptEntry) == 0 {
 			return false

go/neo/parttab_test.go

+// Copyright (C) 2017  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+package neo
+
+import (
+	"testing"
+)
+
+func TestPartTabOperational(t *testing.T) {
+	s1 := UUID(STORAGE, 1)
+	s2 := UUID(STORAGE, 2)
+
+	// create nodeinfo for uuid/state
+	n := func(uuid NodeUUID, state NodeState) NodeInfo {
+		return NodeInfo{UUID: uuid, State: state}	// XXX .Type?
+	}
+
+	// create nodetab with [](uuid, state)
+	N := func(nodeiv ...NodeInfo) *NodeTable {
+		nt := &NodeTable{}
+		for _, nodei := range nodeiv {
+			nt.Update(nodei)
+		}
+		return nt
+	}
+
+	// create cell with uuid/state
+	C := func(uuid NodeUUID, state CellState) Cell {
+		return Cell{CellInfo{UUID: uuid, State: state}}
+	}
+
+	// shortcut to create []Cell
+	v := func(cellv ...Cell) []Cell { return cellv }
+
+	// shortcut to create PartitionTable{[][]Cell}
+	P := func(cellvv ...[]Cell) *PartitionTable {
+		return &PartitionTable{tab: cellvv}
+	}
+
+	var testv = []struct{pt *PartitionTable; nt *NodeTable; operational bool}{
+		// empty parttab is non-operational
+		{P(), N(), false},
+		{P(), N(n(s1, RUNNING)), false},
+
+		// parttab with 1 storage
+		{P(v(C(s1, UP_TO_DATE))),	N(), false},
+		{P(v(C(s1, UP_TO_DATE))),	N(n(s2, RUNNING)), false},
+		{P(v(C(s1, OUT_OF_DATE))),	N(n(s1, RUNNING)), false},
+		{P(v(C(s1, UP_TO_DATE))),	N(n(s1, RUNNING)), true},
+		{P(v(C(s1, FEEDING))),		N(n(s1, RUNNING)), true},
+
+		// TODO more tests
+	}
+
+	for _, tt := range testv {
+		op := tt.pt.OperationalWith(tt.nt)
+		if op != tt.operational {
+			t.Errorf("parttab:\n%s\nnodetab:\n%s\noperational: %v  ; want %v\n",
+				tt.pt, tt.nt, op, tt.operational)
+		}
+	}
+}