From 81b4de39ee778221449ed12980a30d3e7e24ecc0 Mon Sep 17 00:00:00 2001
From: Joffrey JAFFEUX <j.jaffeux@gmail.com>
Date: Tue, 17 Dec 2019 10:55:06 +0100
Subject: [PATCH] FIX: prevents crash in discourse_tagging with empty term
 (#8548)

---
 lib/discourse_tagging.rb                  |  6 ++----
 spec/components/discourse_tagging_spec.rb | 10 ++++++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/discourse_tagging.rb b/lib/discourse_tagging.rb
index 3abeefbe925..94b9f2cf93b 100644
--- a/lib/discourse_tagging.rb
+++ b/lib/discourse_tagging.rb
@@ -222,7 +222,7 @@ module DiscourseTagging
 
     distinct_clause = if opts[:order_popularity]
       "DISTINCT ON (topic_count, name)"
-    elsif opts[:order_search_results]
+    elsif opts[:order_search_results] && opts[:term].present?
       "DISTINCT ON (lower(name) = lower(:cleaned_term), topic_count, name)"
     else
       ""
@@ -278,9 +278,7 @@ module DiscourseTagging
 
     term = opts[:term]
     if term.present?
-      term = term.gsub("_", "\\_")
-      clean_tag(term)
-      term.downcase!
+      term = term.gsub("_", "\\_").downcase
       builder.where("LOWER(name) LIKE :term")
       builder_params[:cleaned_term] = term
       builder_params[:term] = "%#{term}%"
diff --git a/spec/components/discourse_tagging_spec.rb b/spec/components/discourse_tagging_spec.rb
index dcd0f7f1c3d..ee12b4ce37b 100644
--- a/spec/components/discourse_tagging_spec.rb
+++ b/spec/components/discourse_tagging_spec.rb
@@ -129,6 +129,16 @@ describe DiscourseTagging do
         end
       end
 
+      context 'empty term' do
+        it "works with an empty term" do
+          tags = DiscourseTagging.filter_allowed_tags(Guardian.new(user),
+            term: '',
+            order_search_results: true
+          ).map(&:name)
+          expect(sorted_tag_names(tags)).to eq(sorted_tag_names([tag1, tag2, tag3]))
+        end
+      end
+
       context 'tag synonyms' do
         fab!(:base_tag) { Fabricate(:tag, name: 'discourse') }
         fab!(:synonym) { Fabricate(:tag, name: 'discource', target_tag: base_tag) }