From: Avery Pennarun <apenwarr@gmail.com>
Date: Fri, 12 Feb 2010 19:53:19 +0000 (-0500)
Subject: _hashsplit.c: right shifting 32 bits doesn't work.
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=666c08a8d1e99cd319b559e0c0f8c9804c01ced0;p=packages%2Fb%2Fbup.git

_hashsplit.c: right shifting 32 bits doesn't work.

in C, if you do
	uint32_t i = 0xffffffff;
	i >>= 32;

then the answer is 0xffffffff, not 0 as you might expect.  Let's shift it by
less than 32 at a time, which will give the right results.  This fixes a
rare infinite loop when counting the bits in the hashsplit.
---

diff --git a/_hashsplit.c b/_hashsplit.c
index a731454..e78f597 100644
--- a/_hashsplit.c
+++ b/_hashsplit.c
@@ -33,7 +33,8 @@ static int find_ofs(const unsigned char *buf, int len, int *bits)
 	    if (bits)
 	    {
 		*bits = BLOBBITS;
-		for (*bits = BLOBBITS; (sum >> *bits) & 1; (*bits)++)
+		sum >>= BLOBBITS;
+		for (*bits = BLOBBITS; (sum >>= 1) & 1; (*bits)++)
 		    ;
 	    }
 	    return count+1;