From e541c9b64b829761fae3389d1759a72b1d3ccc94 Mon Sep 17 00:00:00 2001
From: Phil Turnbull <philipturnbull@github.com>
Date: Tue, 7 Aug 2018 12:29:06 -0400
Subject: [PATCH] Avoid integer cast issues when deserializing tags

`buffer` contains signed chars, so if a tag length is greater than 128 then it
is treated as a negative value when deserializing. The negative signed char is
then implicitly cast to a large unsigned integer. Explicitly cast the values to
signed chars

Co-authored-by: Rahul Zhade <zhade3@github.com>
---
 src/scanner.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/scanner.cc b/src/scanner.cc
index 0077c98..69e595b 100644
--- a/src/scanner.cc
+++ b/src/scanner.cc
@@ -60,7 +60,7 @@ struct Scanner {
         Tag &tag = tags[j];
         tag.type = static_cast<TagType>(buffer[i++]);
         if (tag.type == CUSTOM) {
-          unsigned name_length = buffer[i++];
+          unsigned name_length = (unsigned char)buffer[i++];
           tag.custom_tag_name.assign(&buffer[i], &buffer[i + name_length]);
           i += name_length;
         }