From 83d2840b6f1a5ec898e441be148ddd3211f11583 Mon Sep 17 00:00:00 2001
From: Bob Halley <source@isc.org>
Date: Tue, 12 Sep 2000 19:26:40 +0000
Subject: [PATCH] fix erroneous isc_bitstring_copy() REQUIRE

---
 CHANGES             |  4 ++++
 lib/isc/bitstring.c | 18 +++++++++---------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/CHANGES b/CHANGES
index 9e08e33107..f9f3734e2f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+ 445.	[bug]		Doing a 0 bit isc_bitstring_copy() of an lsb0
+			bitstring triggered a REQUIRE statement.  The REQUIRE
+			statement was incorrect. [RT #297]
+
  444.	[func]		"recursion denied" messages are always logged at
 			debug level 1, now, rather than sometimes at ERROR.
 			This silences these warnings in the usual case, where
diff --git a/lib/isc/bitstring.c b/lib/isc/bitstring.c
index 4f6a609ded..10a626d15d 100644
--- a/lib/isc/bitstring.c
+++ b/lib/isc/bitstring.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: bitstring.c,v 1.7 2000/08/01 01:29:15 tale Exp $ */
+/* $Id: bitstring.c,v 1.8 2000/09/12 19:26:40 halley Exp $ */
 
 #include <config.h>
 
@@ -90,20 +90,20 @@ isc_bitstring_copy(isc_bitstring_t *source, unsigned int sbitpos,
 	REQUIRE(VALID_BITSTRING(source));
 	REQUIRE(VALID_BITSTRING(target));
 	if (source->lsb0) {
-		REQUIRE(sbitpos < source->length);
-		sbitpos = PADDED(source->size) - sbitpos - 1;
-		REQUIRE(sbitpos >= n - 1);
-		sbitpos -= n - 1;
+		REQUIRE(sbitpos <= source->length);
+		sbitpos = PADDED(source->size) - sbitpos;
+		REQUIRE(sbitpos >= n);
+		sbitpos -= n;
 	} else
 		REQUIRE(sbitpos + n <= source->length);
 	tlast = tbitpos + n;
 	if (target->lsb0) {
 		REQUIRE(tbitpos <= target->length);
-		tbitpos = PADDED(target->size) - tbitpos - 1;
-		REQUIRE(tbitpos >= n - 1);
-		tbitpos -= n - 1;
+		tbitpos = PADDED(target->size) - tbitpos;
+		REQUIRE(tbitpos >= n);
+		tbitpos -= n;
 	} else
-		REQUIRE(tlast<= target->size);
+		REQUIRE(tlast <= target->size);
 
 	if (tlast > target->length)
 		target->length = tlast;