fix GetParentPosts() query

store/sql_post_store.go

@@ -343,9 +343,9 @@ func (s SqlPostStore) getParentsPosts(channelId string, offset int, limit int) S
 			    WHERE
 			        ChannelId = :ChannelId1
 			            AND DeleteAt = 0
-				    AND RootId <> ''
 			    ORDER BY CreateAt DESC
-			    LIMIT :Limit OFFSET :Offset) q3) q1 ON q1.RootId = q2.RootId
+			    LIMIT :Limit OFFSET :Offset) q3
+			    WHERE q3.RootId != '') q1 ON q1.RootId = q2.Id
 			WHERE
 			    ChannelId = :ChannelId2
 			        AND DeleteAt = 0

store/sql_post_store_test.go

@@ -374,7 +374,7 @@ func TestPostStoreGetPostsWtihDetails(t *testing.T) {
 		t.Fatal("invalid order")
 	}
 
-	if len(r1.Posts) != 6 {
+	if len(r1.Posts) != 5 { //the last 4, + o1 (o3 and o2a's parent)
 		t.Fatal("wrong size")
 	}