Fix #66.

impl/memory/datastore_query_execution_test.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package memory
 
 import (
         "fmt"
         "strings"
         "testing"
@@ skipping 493 matching lines @@
                                         },
                                 },
 
                                 {
                                         q:   nq("Kind").Offset(2),
                                         get: []ds.PropertyMap{},
                                 },
                         },
                 },
         }},
+
+        {"regression: avoid index bleedover for common fields in compound indices", []qExStage{
+                {
+                        addIdxs: []*ds.IndexDefinition{
+                                indx("Kind", "A", "B"),
+                                indx("Other", "A", "B"),
+                        },
+                        putEnts: []ds.PropertyMap{
+                                pmap(
+                                        "$key", key("Kind", 1), Next,
+                                        "A", "value", Next,
+                                        "B", "value", Next),
+                        },
+                },
+                {
+                        expect: []qExpect{
+                                {
+                                        q:   nq("Other").Eq("A", "value").Order("B"),
+                                        get: []ds.PropertyMap{},
+                                },
+                        },
+                },
+        }},
 }
 
 func TestQueryExecution(t *testing.T) {
         t.Parallel()
 
         Convey("Test query execution", t, func() {
                 c, err := info.Namespace(Use(context.Background()), "ns")
                 if err != nil {
                         panic(err)
                 }
@@ skipping 137 matching lines @@
 
         v, ok := actual.(error)
         if !ok {
                 return fmt.Sprintf("type of 'actual' must be error, not %T", actual)
         }
         if v == nil || v == ds.Stop {
                 return ""
         }
         return fmt.Sprintf("expected success value, not %v", v)
 }