Fix data setup for reparentShardLocked cases, handle Before == ni…

…l case

Signed-off-by: Andrew Mason <amason@slack-corp.com>

go/vt/vtctl/reparentutil/emergency_reparenter_test.go

@@ -142,6 +142,10 @@ func TestEmergencyReparenter_reparentShardLocked(t *testing.T) {
 						Error:  nil,
 					},
 				},
+				SetMasterResults: map[string]error{
+					"zone1-0000000100": nil,
+					"zone1-0000000101": nil,
+				},
 				StopReplicationAndGetStatusResults: map[string]struct {
 					Status     *replicationdatapb.Status
 					StopStatus *replicationdatapb.StopReplicationStatus
@@ -240,6 +244,10 @@ func TestEmergencyReparenter_reparentShardLocked(t *testing.T) {
 						Error:  nil,
 					},
 				},
+				SetMasterResults: map[string]error{
+					"zone1-0000000100": nil,
+					"zone1-0000000102": nil,
+				},
 				StopReplicationAndGetStatusResults: map[string]struct {
 					Status     *replicationdatapb.Status
 					StopStatus *replicationdatapb.StopReplicationStatus

go/vt/vtctl/reparentutil/replication.go

@@ -142,6 +142,10 @@ func FindValidEmergencyReparentCandidates(
 // ReplicaWasRunning returns true if a StopReplicationStatus indicates that the
 // replica had running replication threads before being stopped.
 func ReplicaWasRunning(stopStatus *replicationdatapb.StopReplicationStatus) bool {
+	if stopStatus.Before == nil {
+		return false
+	}
+
 	return stopStatus.Before.IoThreadRunning || stopStatus.Before.SqlThreadRunning
 }
 

go/vt/vtctl/reparentutil/replication_test.go

@@ -760,6 +760,13 @@ func TestReplicaWasRunning(t *testing.T) {
 			},
 			expected: false,
 		},
+		{
+			name: "status.Before is nil means we were not running",
+			in: &replicationdatapb.StopReplicationStatus{
+				Before: nil,
+			},
+			expected: false,
+		},
 	}
 
 	for _, tt := range tests {