From 17e3392052984a6c84d1d9bb6abb7baf1de5ea3f Mon Sep 17 00:00:00 2001
From: Jon Siwek <jsiwek@corelight.com>
Date: Thu, 17 Sep 2020 21:08:57 -0700
Subject: [PATCH] Avoid unary negation of INT64_MIN in modp_litoa10

Overlow can occur in that case, which is undefined behavior.
---
 src/modp_numtoa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/modp_numtoa.c b/src/modp_numtoa.c
index e7b074d876..ab6b2c95e8 100644
--- a/src/modp_numtoa.c
+++ b/src/modp_numtoa.c
@@ -57,7 +57,7 @@ void modp_uitoa10(uint32_t value, char* str)
 void modp_litoa10(int64_t value, char* str)
 {
     char* wstr=str;
-    uint64_t uvalue = (value < 0) ? -value : value;
+    uint64_t uvalue = (value < 0) ? (value == INT64_MIN ? (uint64_t)(INT64_MAX) + 1 : -value) : value;
 
     // Conversion. Number is reversed.
     do *wstr++ = (char)(48 + (uvalue % 10)); while(uvalue /= 10);