From bf82e6cdedfc85d5361a8b68f6a1fd9b55d12a6d Mon Sep 17 00:00:00 2001
From: kay delaney <45561153+kaydelaney@users.noreply.github.com>
Date: Fri, 16 Aug 2019 15:10:22 +0100
Subject: [PATCH] Explore: Fixes error when switching from prometheus to loki
 data sources (#18599)

Closes #18594
Closes #18596
---
 public/app/features/explore/QueryField.tsx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/public/app/features/explore/QueryField.tsx b/public/app/features/explore/QueryField.tsx
index 0bbc97ba16c..9ad5d57f6f4 100644
--- a/public/app/features/explore/QueryField.tsx
+++ b/public/app/features/explore/QueryField.tsx
@@ -115,7 +115,7 @@ export class QueryField extends React.PureComponent<QueryFieldProps, QueryFieldS
     if (initialQuery !== prevProps.initialQuery) {
       // and we have a version that differs
       if (initialQuery !== Plain.serialize(value)) {
-        this.setState({ value: makeValue(initialQuery, syntax) });
+        this.setState({ value: makeValue(initialQuery || '', syntax) });
       }
     }