From da93e236a93f5a6d9365986175acfc6d04823785 Mon Sep 17 00:00:00 2001
From: Drew Bailey <2614075+drewbailey@users.noreply.github.com>
Date: Mon, 6 Apr 2020 12:25:50 -0400
Subject: [PATCH] guard against nil maps

---
 nomad/structs/diff.go | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/nomad/structs/diff.go b/nomad/structs/diff.go
index 812a28e17ad..34533c0584c 100644
--- a/nomad/structs/diff.go
+++ b/nomad/structs/diff.go
@@ -225,15 +225,17 @@ func (tg *TaskGroup) Diff(other *TaskGroup, contextual bool) (*TaskGroupDiff, er
 	}
 
 	// ShutdownDelay diff
-	if tg.ShutdownDelay == nil {
-		oldPrimitiveFlat["ShutdownDelay"] = ""
-	} else {
-		oldPrimitiveFlat["ShutdownDelay"] = fmt.Sprintf("%d", *tg.ShutdownDelay)
-	}
-	if other.ShutdownDelay == nil {
-		newPrimitiveFlat["ShutdownDelay"] = ""
-	} else {
-		newPrimitiveFlat["ShutdownDelay"] = fmt.Sprintf("%d", *other.ShutdownDelay)
+	if oldPrimitiveFlat != nil && newPrimitiveFlat != nil {
+		if tg.ShutdownDelay == nil {
+			oldPrimitiveFlat["ShutdownDelay"] = ""
+		} else {
+			oldPrimitiveFlat["ShutdownDelay"] = fmt.Sprintf("%d", *tg.ShutdownDelay)
+		}
+		if other.ShutdownDelay == nil {
+			newPrimitiveFlat["ShutdownDelay"] = ""
+		} else {
+			newPrimitiveFlat["ShutdownDelay"] = fmt.Sprintf("%d", *other.ShutdownDelay)
+		}
 	}
 
 	// Diff the primitive fields.