From c3f267db8fe1c3a7ed98662a31ddb7172a166e10 Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Thu, 8 Oct 2020 09:49:35 -0400
Subject: [PATCH] Improve bad filter detection in element picker

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1280
---
 src/js/epicker-ui.js | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/js/epicker-ui.js b/src/js/epicker-ui.js
index 2242ec538..15eefafe0 100644
--- a/src/js/epicker-ui.js
+++ b/src/js/epicker-ui.js
@@ -71,9 +71,17 @@ const filterFromTextarea = function() {
     if ( s === '' ) { return ''; }
     const pos = s.indexOf('\n');
     const filter = pos === -1 ? s.trim() : s.slice(0, pos).trim();
-    staticFilteringParser.analyze(filter);
-    staticFilteringParser.analyzeExtra();
-    return staticFilteringParser.shouldDiscard() ? '!' : filter;
+    const sfp = staticFilteringParser;
+    sfp.analyze(filter);
+    sfp.analyzeExtra();
+    if (
+        sfp.category !== sfp.CATStaticExtFilter &&
+        sfp.category !== sfp.CATStaticNetFilter ||
+        sfp.shouldDiscard()
+    ) {
+        return '!';
+    }
+    return filter;
 };
 
 /******************************************************************************/