From 75b360af4ae3949c003e39d57dad43238e3178c2 Mon Sep 17 00:00:00 2001
From: Billy Donahue <BillyDonahue@users.noreply.github.com>
Date: Wed, 13 May 2020 18:37:02 -0400
Subject: [PATCH] spot fix #1171: isprint argument must be representable as
 unsigned char (#1173)

---
 src/lib_json/json_writer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib_json/json_writer.cpp b/src/lib_json/json_writer.cpp
index cb528b8..56ee65e 100644
--- a/src/lib_json/json_writer.cpp
+++ b/src/lib_json/json_writer.cpp
@@ -178,7 +178,7 @@ String valueToString(bool value) { return value ? "true" : "false"; }
 static bool isAnyCharRequiredQuoting(char const* s, size_t n) {
   assert(s || !n);
 
-  return std::any_of(s, s + n, [](int c) {
+  return std::any_of(s, s + n, [](unsigned char c) {
     return c == '\\' || c == '"' || !std::isprint(c);
   });
 }