From 0bcb7669e77adc958ee66a97fe9172898cb8131d Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Thu, 2 Apr 2020 10:39:31 -0400
Subject: [PATCH] Fix exception thrown when a stock asset is removed

Related feedback:
- https://www.reddit.com/r/uMatrix/comments/ftebgz/
---
 src/js/storage.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/js/storage.js b/src/js/storage.js
index 78ababc..a5d6bd4 100644
--- a/src/js/storage.js
+++ b/src/js/storage.js
@@ -496,9 +496,19 @@ self.addEventListener('rawSettingsChanged', ( ) => {
     const addedCount = this.ubiquitousBlacklistRef.addedCount;
     const addCount = this.ubiquitousBlacklistRef.addCount;
 
-    this.mergeHostsFileContent(details.content);
+    // https://www.reddit.com/r/uMatrix/comments/ftebgz/
+    //   Be ready to deal with a removed asset.
+
+    if ( typeof details.content === 'string' && details.content !== '' ) {
+        this.mergeHostsFileContent(details.content);
+    }
 
     const hostsFileMeta = this.liveHostsFiles.get(details.assetKey);
+    if ( hostsFileMeta === undefined ) {
+        this.liveHostsFiles.delete(details.assetKey);
+        return;
+    }
+
     hostsFileMeta.entryCount =
         this.ubiquitousBlacklistRef.addCount - addCount;
     hostsFileMeta.entryUsedCount =