From 0253f6fe05e8aa5d5382ef7a05d5c956a11fac94 Mon Sep 17 00:00:00 2001
From: Stuart Carnie <stuart@influxdata.com>
Date: Tue, 29 May 2018 09:39:51 -0700
Subject: [PATCH] fix(tsdb/engine/tsm1): Fix panic when closing cursor multiple
 times

Fixes #9909
---
 tsdb/engine/tsm1/batch_cursor.gen.go      | 30 +++++++++++++++--------
 tsdb/engine/tsm1/batch_cursor.gen.go.tmpl |  6 +++--
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/tsdb/engine/tsm1/batch_cursor.gen.go b/tsdb/engine/tsm1/batch_cursor.gen.go
index f9da17ed152..c3dca83db07 100644
--- a/tsdb/engine/tsm1/batch_cursor.gen.go
+++ b/tsdb/engine/tsm1/batch_cursor.gen.go
@@ -99,8 +99,10 @@ func (c *floatAscendingBatchCursor) Err() error { return nil }
 
 // close closes the cursor and any dependent cursors.
 func (c *floatAscendingBatchCursor) Close() {
-	c.tsm.keyCursor.Close()
-	c.tsm.keyCursor = nil
+	if c.tsm.keyCursor != nil {
+		c.tsm.keyCursor.Close()
+		c.tsm.keyCursor = nil
+	}
 	c.cache.values = nil
 	c.tsm.values = nil
 }
@@ -398,8 +400,10 @@ func (c *integerAscendingBatchCursor) Err() error { return nil }
 
 // close closes the cursor and any dependent cursors.
 func (c *integerAscendingBatchCursor) Close() {
-	c.tsm.keyCursor.Close()
-	c.tsm.keyCursor = nil
+	if c.tsm.keyCursor != nil {
+		c.tsm.keyCursor.Close()
+		c.tsm.keyCursor = nil
+	}
 	c.cache.values = nil
 	c.tsm.values = nil
 }
@@ -697,8 +701,10 @@ func (c *unsignedAscendingBatchCursor) Err() error { return nil }
 
 // close closes the cursor and any dependent cursors.
 func (c *unsignedAscendingBatchCursor) Close() {
-	c.tsm.keyCursor.Close()
-	c.tsm.keyCursor = nil
+	if c.tsm.keyCursor != nil {
+		c.tsm.keyCursor.Close()
+		c.tsm.keyCursor = nil
+	}
 	c.cache.values = nil
 	c.tsm.values = nil
 }
@@ -996,8 +1002,10 @@ func (c *stringAscendingBatchCursor) Err() error { return nil }
 
 // close closes the cursor and any dependent cursors.
 func (c *stringAscendingBatchCursor) Close() {
-	c.tsm.keyCursor.Close()
-	c.tsm.keyCursor = nil
+	if c.tsm.keyCursor != nil {
+		c.tsm.keyCursor.Close()
+		c.tsm.keyCursor = nil
+	}
 	c.cache.values = nil
 	c.tsm.values = nil
 }
@@ -1295,8 +1303,10 @@ func (c *booleanAscendingBatchCursor) Err() error { return nil }
 
 // close closes the cursor and any dependent cursors.
 func (c *booleanAscendingBatchCursor) Close() {
-	c.tsm.keyCursor.Close()
-	c.tsm.keyCursor = nil
+	if c.tsm.keyCursor != nil {
+		c.tsm.keyCursor.Close()
+		c.tsm.keyCursor = nil
+	}
 	c.cache.values = nil
 	c.tsm.values = nil
 }
diff --git a/tsdb/engine/tsm1/batch_cursor.gen.go.tmpl b/tsdb/engine/tsm1/batch_cursor.gen.go.tmpl
index a10c082dd0a..457af10eb2a 100644
--- a/tsdb/engine/tsm1/batch_cursor.gen.go.tmpl
+++ b/tsdb/engine/tsm1/batch_cursor.gen.go.tmpl
@@ -67,8 +67,10 @@ func (c *{{.name}}AscendingBatchCursor) Err() error        { return nil }
 
 // close closes the cursor and any dependent cursors.
 func (c *{{.name}}AscendingBatchCursor) Close() {
-	c.tsm.keyCursor.Close()
-	c.tsm.keyCursor = nil
+	if c.tsm.keyCursor != nil {
+		c.tsm.keyCursor.Close()
+		c.tsm.keyCursor = nil
+	}
 	c.cache.values = nil
 	c.tsm.values = nil
 }