FIX: Allow searching for unsolved posts with tags

When using the `status:unsolved` search filter, the plugin was only
returning results from topics in categories where solved was enabled.

This commit changes the search query to also include topics with tags
that have solved enabled via the `enable_solved_tags` site setting.

This fixes the `status:unsolved tags:tag1` search query.

plugin.rb

@@ -368,20 +368,28 @@ def self.skip_db?
           )",
         )
       else
+        tag_ids = Tag.where(name: SiteSetting.enable_solved_tags.split("|")).pluck(:id)
+
         posts.where(
           "topics.id NOT IN (
           SELECT tc.topic_id
           FROM topic_custom_fields tc
           WHERE tc.name = '#{::DiscourseSolved::ACCEPTED_ANSWER_POST_ID_CUSTOM_FIELD}' AND
                           tc.value IS NOT NULL
-          ) AND topics.id IN (
+          ) AND (topics.id IN (
             SELECT top.id
             FROM topics top
             INNER JOIN category_custom_fields cc
             ON top.category_id = cc.category_id
             WHERE cc.name = '#{::DiscourseSolved::ENABLE_ACCEPTED_ANSWERS_CUSTOM_FIELD}' AND
                           cc.value = 'true'
-          )",
+          ) OR topics.id IN (
+            SELECT top.id
+            FROM topics top
+            INNER JOIN topic_tags tt
+            ON top.id = tt.topic_id
+            WHERE tt.tag_id IN (?)
+          ))", tag_ids
         )
       end
     end

spec/integration/solved_spec.rb

@@ -63,6 +63,7 @@
         category_custom_field.save
         category
       end
+      fab!(:tag) { Fabricate(:tag, name: "tag1") }
       fab!(:topic_unsolved) do
         Fabricate(
           :custom_topic,
@@ -71,6 +72,13 @@
           custom_topic_name: ::DiscourseSolved::ACCEPTED_ANSWER_POST_ID_CUSTOM_FIELD,
         )
       end
+      fab!(:topic_unsolved_2) do
+        Fabricate(
+          :topic,
+          user: user,
+          tags: [tag],
+        )
+      end
       fab!(:topic_solved) do
         Fabricate(
           :custom_topic,
@@ -96,6 +104,7 @@
         )
       end
       fab!(:post_unsolved) { Fabricate(:post, topic: topic_unsolved) }
+      fab!(:post_unsolved_2) { Fabricate(:post, topic: topic_unsolved_2) }
       fab!(:post_solved) do
         post = Fabricate(:post, topic: topic_solved)
         DiscourseSolved.accept_answer!(post, Discourse.system_user)
@@ -105,10 +114,12 @@
       fab!(:post_disabled_2) { Fabricate(:post, topic: topic_disabled_2) }
 
       before do
+        SiteSetting.enable_solved_tags = tag.name
         SearchIndexer.enable
         Jobs.run_immediately!
 
         SearchIndexer.index(topic_unsolved, force: true)
+        SearchIndexer.index(topic_unsolved_2, force: true)
         SearchIndexer.index(topic_solved, force: true)
         SearchIndexer.index(topic_disabled_1, force: true)
         SearchIndexer.index(topic_disabled_2, force: true)
@@ -120,17 +131,23 @@
         describe "when allow solved on all topics is disabled" do
           before { SiteSetting.allow_solved_on_all_topics = false }
 
-          it "only returns posts where 'Allow topic owner and staff to mark a reply as the solution' is enabled and post is not solved" do
+          it "only returns unsolved posts from categories and tags where solving is enabled" do
             result = Search.execute("status:unsolved")
-            expect(result.posts.pluck(:id)).to match_array([post_unsolved.id])
+            expect(result.posts.pluck(:id)).to match_array([post_unsolved.id, post_unsolved_2.id])
+          end
+
+          it "returns the correct results when combining search with a tag" do
+            result = Search.execute("status:unsolved tag:tag1")
+            expect(result.posts.pluck(:id)).to match_array([post_unsolved_2.id])
           end
         end
+
         describe "when allow solved on all topics is enabled" do
           before { SiteSetting.allow_solved_on_all_topics = true }
           it "only returns posts where the post is not solved" do
             result = Search.execute("status:unsolved")
             expect(result.posts.pluck(:id)).to match_array(
-              [post_unsolved.id, post_disabled_1.id, post_disabled_2.id],
+              [post_unsolved.id, post_unsolved_2.id, post_disabled_1.id, post_disabled_2.id],
             )
           end
         end