From 7807107bfa241f01d9ca0e841599ae661f02a340 Mon Sep 17 00:00:00 2001
From: ggrieco-tob <gustavo.grieco@trailofbits.com>
Date: Mon, 18 Sep 2023 18:53:10 +0200
Subject: [PATCH] make sure hex output is padded properly

---
 lib/Echidna/ABI.hs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/Echidna/ABI.hs b/lib/Echidna/ABI.hs
index f4b174dd2..e3532150a 100644
--- a/lib/Echidna/ABI.hs
+++ b/lib/Echidna/ABI.hs
@@ -20,6 +20,7 @@ import Data.List (intercalate)
 import Data.List.NonEmpty (NonEmpty)
 import Data.List.NonEmpty qualified as NE
 import Data.Maybe (fromMaybe, catMaybes)
+import Text.Printf (printf)
 import Data.Text (Text)
 import Data.Text qualified as T
 import Data.Text.Encoding (encodeUtf8)
@@ -71,7 +72,7 @@ ppAbiValue = \case
   AbiInt  _ n         -> show n
   AbiAddress n        -> "0x" <> showHex n ""
   AbiBool b           -> if b then "true" else "false"
-  AbiBytes 32 b       -> "0x" <> BS.foldr showHex "" b
+  AbiBytes 32 b       -> "0x" <> (BS.foldr (\x -> (<>) (printf "%02x" x)) "" b)
   AbiBytes _ b        -> show b
   AbiBytesDynamic b   -> show b
   AbiString s         -> show s