From c503ffa871555b5cf37abdf00723cb7e35209fdf Mon Sep 17 00:00:00 2001
From: Kamil Dziedzic <arvenil@klecza.pl>
Date: Mon, 21 Aug 2017 18:21:50 +0200
Subject: [PATCH] sanity check

---
 src/go/mongolib/fingerprinter/fingerprinter.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/go/mongolib/fingerprinter/fingerprinter.go b/src/go/mongolib/fingerprinter/fingerprinter.go
index e434d4f0..47314f48 100644
--- a/src/go/mongolib/fingerprinter/fingerprinter.go
+++ b/src/go/mongolib/fingerprinter/fingerprinter.go
@@ -98,6 +98,9 @@ func (f *Fingerprint) Fingerprint(doc proto.SystemProfile) (string, error) {
 			collection = ns[1]
 		}
 	default:
+		if query.Len() == 0 {
+			break
+		}
 		// first key is operation type
 		op = query.D[0].Name
 		collection, _ = query.D[0].Value.(string)