From ba900f4ad6a61d854e203af0ba0bb085e6d3b506 Mon Sep 17 00:00:00 2001
From: "byte[]" <byteslice@airmail.cc>
Date: Thu, 18 Mar 2021 01:29:21 -0400
Subject: [PATCH] boost values must be non-negative since ES7 (bm25 forbids
 negative scores)

---
 lib/philomena/search/parser.ex | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/philomena/search/parser.ex b/lib/philomena/search/parser.ex
index 00bbed6a..f89290ee 100644
--- a/lib/philomena/search/parser.ex
+++ b/lib/philomena/search/parser.ex
@@ -107,9 +107,12 @@ defmodule Philomena.Search.Parser do
 
   defp search_boost(parser, tokens) do
     case search_not(parser, tokens) do
-      {:ok, {child, [{:boost, value} | r_tokens]}} ->
+      {:ok, {child, [{:boost, value} | r_tokens]}} when value >= 0 ->
         {:ok, {%{function_score: %{query: child, boost: value}}, r_tokens}}
 
+      {:ok, {_child, [{:boost, _value} | _r_tokens]}} ->
+        {:error, "Boost value must be non-negative."}
+
       value ->
         value
     end