From f28ded9fbb8ae763381aedcb1ac397800009b654 Mon Sep 17 00:00:00 2001
From: Michael Smith <msmith@xiph.org>
Date: Mon, 14 Mar 2005 23:41:11 +0000
Subject: [PATCH] A bug report indirectly suggested the base64 decode code was
 confusing (as the treatment of padding was un-obvious), so added a comment
 explaining it.

svn path=/icecast/trunk/icecast/; revision=9075
---
 src/util.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/util.c b/src/util.c
index 6e2db5c0..64803f81 100644
--- a/src/util.c
+++ b/src/util.c
@@ -463,6 +463,10 @@ char *util_base64_decode(unsigned char *input)
         }
 
         *out++ = vals[0]<<2 | vals[1]>>4;
+        /* vals[3] and (if that is) vals[2] can be '=' as padding, which is
+           looked up in the base64decode table as '-1'. Check for this case,
+           and output zero-terminators instead of characters if we've got
+           padding. */
         if(vals[2] >= 0)
             *out++ = ((vals[1]&0x0F)<<4) | (vals[2]>>2);
         else