From 47b7f512da1143818b41006b6c265804239d9804 Mon Sep 17 00:00:00 2001
From: Nathaniel Cook <nvcook42@gmail.com>
Date: Fri, 27 Jul 2018 09:15:28 -0600
Subject: [PATCH] fix: Panic in query/controller on Statistics

---
 query/control/controller.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/query/control/controller.go b/query/control/controller.go
index 4c610b8a4c..5cdff02c1b 100644
--- a/query/control/controller.go
+++ b/query/control/controller.go
@@ -435,6 +435,9 @@ func (q *Query) Done() {
 // Statistics reports the statisitcs for the query.
 // The statisitcs are not complete until the query is finished.
 func (q *Query) Statistics() query.Statistics {
+	q.mu.Lock()
+	defer q.mu.Lock()
+
 	stats := query.Statistics{}
 	stats.TotalDuration = q.parentSpan.Duration
 	if q.compileSpan != nil {
@@ -453,7 +456,9 @@ func (q *Query) Statistics() query.Statistics {
 		stats.ExecuteDuration = q.executeSpan.Duration
 	}
 	stats.Concurrency = q.concurrency
-	stats.MaxAllocated = q.alloc.Max()
+	if q.alloc != nil {
+		stats.MaxAllocated = q.alloc.Max()
+	}
 	return stats
 }