btree/bt_split.c: Apply patch.1.2: Check for last page in a condition.

"DB 1.85 core dumps on certain data sets when using the B+tree access
method."

http://download.oracle.com/berkeley-db/patches/db/1.85/patch.1.2

btree/bt_split.c

@@ -673,7 +673,7 @@ bt_psplit(t, h, l, r, pskip, ilen)
 		 * where we decide to try and copy too much onto the left page.
 		 * Make sure that doesn't happen.
 		 */
-		if (skip <= off && used + nbytes >= full) {
+		if (skip <= off && used + nbytes >= full || nxt == top - 1) {
 			--off;
 			break;
 		}