From d733f2ec265d358d55370a79bb9d550a2d0ad40e Mon Sep 17 00:00:00 2001
From: =?utf8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
Date: Mon, 23 Oct 2023 12:51:19 +0100
Subject: [PATCH] basenc: --base16: support lower case hex digits

* src/basenc.c (base16_decode_ctx): Convert to uppercase
before converting from hex.
* tests/basenc/basenc.pl: Add a test case.
* NEWS: Mention the change in behavior.
Addresses https://bugs.gnu.org/66698
---
 NEWS                   | 3 +++
 src/basenc.c           | 2 +-
 tests/basenc/basenc.pl | 1 +
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 93f98b99d8..1dfeb7390a 100644
--- a/NEWS
+++ b/NEWS
@@ -19,6 +19,9 @@ GNU coreutils NEWS                                    -*- outline -*-
   base32 and base64 no longer require padding when decoding.
   Previously an error was given for non padded encoded data.
 
+  basenc --base16 -d now supports lower case hexadecimal characters.
+  Previously an error was given for lower case hex digits.
+
   ls --dired now implies long format output without hyperlinks enabled,
   and will take precedence over previously specified formats or hyperlink mode.
 
diff --git a/src/basenc.c b/src/basenc.c
index 12021e9008..74cf03a49b 100644
--- a/src/basenc.c
+++ b/src/basenc.c
@@ -577,7 +577,7 @@ base16_decode_ctx (struct base_decode_context *ctx,
           continue;
         }
 
-      int nib = *in++;
+      int nib = c_toupper (*in++);
       if ('0' <= nib && nib <= '9')
         nib -= '0';
       else if ('A' <= nib && nib <= 'F')
diff --git a/tests/basenc/basenc.pl b/tests/basenc/basenc.pl
index de20d2dbcf..2b0e79e932 100755
--- a/tests/basenc/basenc.pl
+++ b/tests/basenc/basenc.pl
@@ -159,6 +159,7 @@ my @Tests =
  ['b16_7', '--base16 -d',     {IN=>'G'}, {EXIT=>1},
   {ERR=>"$prog: invalid input\n"}],
  ['b16_8', '--base16 -d',     {IN=>"AB\nCD"}, {OUT=>"\xAB\xCD"}],
+ ['b16_9', '--base16 -d',     {IN=>lc ($base16_out)},  {OUT=>$base16_in}],
 
 
 
-- 
2.47.2