From e4fba98c6b7f8ec229c9025891912212ff11cbbb Mon Sep 17 00:00:00 2001
From: davidby-influx <72418212+davidby-influx@users.noreply.github.com>
Date: Mon, 18 Mar 2024 21:57:39 -0700
Subject: [PATCH] fix: do not panic when empty tags are queried (#24784)
 (#24787)

Do not panic if a cursor array is nil and the number
of timestamps is retrieved.

closes https://github.com/influxdata/influxdb/issues/24536

(cherry picked from commit bc80e881fa34aef4145007aa510ffe3e78d3e7ab)
---
 tsdb/cursors/arrayvalues.gen.go      | 36 +++++++++++++++++++++++-----
 tsdb/cursors/arrayvalues.gen.go.tmpl |  6 ++++-
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/tsdb/cursors/arrayvalues.gen.go b/tsdb/cursors/arrayvalues.gen.go
index 9eaffa8e40d..36a80792101 100644
--- a/tsdb/cursors/arrayvalues.gen.go
+++ b/tsdb/cursors/arrayvalues.gen.go
@@ -27,7 +27,11 @@ func (a *FloatArray) MaxTime() int64 {
 }
 
 func (a *FloatArray) Len() int {
-	return len(a.Timestamps)
+	if a != nil {
+		return len(a.Timestamps)
+	} else {
+		return 0
+	}
 }
 
 // search performs a binary search for UnixNano() v in a
@@ -224,7 +228,11 @@ func (a *IntegerArray) MaxTime() int64 {
 }
 
 func (a *IntegerArray) Len() int {
-	return len(a.Timestamps)
+	if a != nil {
+		return len(a.Timestamps)
+	} else {
+		return 0
+	}
 }
 
 // search performs a binary search for UnixNano() v in a
@@ -421,7 +429,11 @@ func (a *UnsignedArray) MaxTime() int64 {
 }
 
 func (a *UnsignedArray) Len() int {
-	return len(a.Timestamps)
+	if a != nil {
+		return len(a.Timestamps)
+	} else {
+		return 0
+	}
 }
 
 // search performs a binary search for UnixNano() v in a
@@ -618,7 +630,11 @@ func (a *StringArray) MaxTime() int64 {
 }
 
 func (a *StringArray) Len() int {
-	return len(a.Timestamps)
+	if a != nil {
+		return len(a.Timestamps)
+	} else {
+		return 0
+	}
 }
 
 // search performs a binary search for UnixNano() v in a
@@ -815,7 +831,11 @@ func (a *BooleanArray) MaxTime() int64 {
 }
 
 func (a *BooleanArray) Len() int {
-	return len(a.Timestamps)
+	if a != nil {
+		return len(a.Timestamps)
+	} else {
+		return 0
+	}
 }
 
 // search performs a binary search for UnixNano() v in a
@@ -1010,7 +1030,11 @@ func (a *TimestampArray) MaxTime() int64 {
 }
 
 func (a *TimestampArray) Len() int {
-	return len(a.Timestamps)
+	if a != nil {
+		return len(a.Timestamps)
+	} else {
+		return 0
+	}
 }
 
 // search performs a binary search for UnixNano() v in a
diff --git a/tsdb/cursors/arrayvalues.gen.go.tmpl b/tsdb/cursors/arrayvalues.gen.go.tmpl
index 3e7632aeeb9..217cebd2cc7 100644
--- a/tsdb/cursors/arrayvalues.gen.go.tmpl
+++ b/tsdb/cursors/arrayvalues.gen.go.tmpl
@@ -29,7 +29,11 @@ func (a *{{ $typename }}) MaxTime() int64 {
 }
 
 func (a *{{ $typename}}) Len() int {
-	return len(a.Timestamps)
+    if a != nil {
+	    return len(a.Timestamps)
+	} else {
+	    return 0
+	}
 }
 
 // search performs a binary search for UnixNano() v in a