From a3e5378d14683119bad31687e6de5cd4ef5a6434 Mon Sep 17 00:00:00 2001
From: Dustin Spicuzza <dustin@virtualroadside.com>
Date: Mon, 25 Dec 2017 23:03:22 -0500
Subject: [PATCH] SPI: Check for null (#850)

---
 wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java
index 910a016087..dd119c8521 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java
@@ -544,8 +544,10 @@ public class SPI {
    * Frees the accumulator.
    */
   public void freeAccumulator() {
-    m_accum.free();
-    m_accum = null;
+    if (m_accum != null) {
+      m_accum.free();
+      m_accum = null;
+    }
     freeAuto();
   }