Merge pull request #236 from Chia-Network/offer-v2

Update offer puzzle to v2

docs/primitives/offers.md

@@ -17,7 +17,7 @@ You can use a wallet to generate an offer file for a given trade, then distribut
 
 ## Settlement Payments Code {#code}
 
-This is the source code of the settlement payments puzzle, which can also be found in the chia-blockchain repository in the puzzle [`settlement_payments.clvm`](https://github.com/Chia-Network/chia-blockchain/blob/164fd158c8626893bc45ba00b87ae69d2ab5f8b7/chia/wallet/puzzles/settlement_payments.clvm).
+This is the source code of the settlement payments puzzle, which can also be found in the chia-blockchain repository in the puzzle [`settlement_payments.clvm`](https://github.com/Chia-Network/chia-blockchain/blob/8224d2fd657780b224a1fc40d3081ce734d70016/chia/wallet/puzzles/settlement_payments.clsp).
 
 <details>
   <summary>Expand Settlement Payments Puzzle</summary>
@@ -31,25 +31,29 @@ This is the source code of the settlement payments puzzle, which can also be fou
   ;; The idea is the other side of this trade requires observing the announcement from a
   ;; `settlement_payments` puzzle hash as a condition of one or more coin spends.
 
-  (include condition_codes.clvm)
+  (include condition_codes.clib)
+  (include utility_macros.clib)
 
   (defun sha256tree (TREE)
-     (if (l TREE)
-         (sha256 2 (sha256tree (f TREE)) (sha256tree (r TREE)))
-         (sha256 1 TREE)
-     )
+    (if (l TREE)
+        (sha256 2 (sha256tree (f TREE)) (sha256tree (r TREE)))
+        (sha256 1 TREE)
+    )
   )
 
   (defun create_coins_for_payment (payment_params so_far)
     (if payment_params
-        (c (c CREATE_COIN (f payment_params)) (create_coins_for_payment (r payment_params) so_far))
+        (assert (> (f (r (f payment_params))) 0)  ; assert the amount is positive
+          ; then
+          (c (c CREATE_COIN (f payment_params)) (create_coins_for_payment (r payment_params) so_far))
+        )
         so_far
     )
   )
 
   (defun-inline create_announcement_for_payment (notarized_payment)
-      (list CREATE_PUZZLE_ANNOUNCEMENT
-            (sha256tree notarized_payment))
+    (list CREATE_PUZZLE_ANNOUNCEMENT
+    (sha256tree notarized_payment))
   )
 
   (defun-inline augment_condition_list (notarized_payment so_far)