From 95260b8dcf23fc315e2ea1c62f46c07681783d42 Mon Sep 17 00:00:00 2001
From: Jack Gerrits <jackgerrits@users.noreply.github.com>
Date: Tue, 15 Jan 2019 17:21:13 -0500
Subject: [PATCH] Add check for hash_inv when creating json parser (#1711)

---
 vowpalwabbit/parser.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/vowpalwabbit/parser.cc b/vowpalwabbit/parser.cc
index a3cbd01a654..e1b0d2d90e8 100644
--- a/vowpalwabbit/parser.cc
+++ b/vowpalwabbit/parser.cc
@@ -642,7 +642,8 @@ void enable_sources(vw& all, bool quiet, size_t passes)
       if (all.opts_n_args.vm.count("json") || all.opts_n_args.vm.count("dsjson"))
       {
         // TODO: change to class with virtual method
-        if (all.audit)
+        // --invert_hash requires the audit parser version to save the extra information.
+        if (all.audit || all.hash_inv)
         {
           all.p->reader = &read_features_json<true>;
           all.p->audit = true;