Add payload field to SubMsg and Reply

CHANGELOG.md

@@ -6,6 +6,15 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Added
+
+- cosmwasm-std: Add new field `payload` to `SubMsg` and `Reply`. This is binary
+  data the contract can set in a contract specific format and get back then the
+  `reply` entry point is called. `SubMsg::with_payload` allows setting the
+  payload on an existing `SubMsg`. ([#2008])
+
+[#2008]: https://github.com/CosmWasm/cosmwasm/pull/2008
+
 ### Changed
 
 - cosmwasm-vm: Limit total number of function parameters in

MIGRATING.md

@@ -221,6 +221,47 @@ major releases of `cosmwasm`. Note that you can also view the
   +}))?;
   ```
 
+- A new `payload` field allows you to send arbitrary data from the original
+  contract into the `reply`. If you construct `SubMsg` manually, add the
+  `payload` field:
+
+  ```diff
+   SubMsg {
+       id: 12,
+  +    payload: Binary::default(),
+       msg: my_bank_send,
+       gas_limit: Some(12345u64),
+       reply_on: ReplyOn::Always,
+   },
+  ```
+
+  or with data:
+
+  ```diff
+   SubMsg {
+       id: 12,
+  +    payload: Binary::new(vec![9, 8, 7, 6, 5]),
+       msg: my_bank_send,
+       gas_limit: Some(12345u64),
+       reply_on: ReplyOn::Always,
+   },
+  ```
+
+  If you use a constructor function, you can set the payload as follows:
+
+  ```diff
+   SubMsg::new(BankMsg::Send {
+     to_address: payout,
+     amount: coins(123456u128,"gold")
+   })
+  +.with_payload(vec![9, 8, 7, 6, 5])
+  ```
+
+  The payload data will then be available in the new field `Reply.payload` in
+  the `reply` entry point. This functionality is an optional addition introduced
+  in 2.0. To keep the CosmWasm 1.x behaviour, just set payload to
+  `Binary::default()`.
+
 ## 1.4.x -> 1.5.0
 
 - Update `cosmwasm-*` dependencies in Cargo.toml (skip the ones you don't use):

contracts/ibc-reflect/src/contract.rs

@@ -400,11 +400,13 @@ mod tests {
             res.events[0]
         );
         let id = res.messages[0].id;
+        let payload = res.messages[0].payload.clone();
 
         // fake a reply and ensure this works
         #[allow(deprecated)]
         let response = Reply {
             id,
+            payload,
             gas_used: 1234567,
             result: SubMsgResult::Ok(SubMsgResponse {
                 events: fake_events(&account),
@@ -461,6 +463,7 @@ mod tests {
         // and set up a reflect account
         assert_eq!(1, res.messages.len());
         let id = res.messages[0].id;
+        let payload = res.messages[0].payload.clone();
         if let CosmosMsg::Wasm(WasmMsg::Instantiate {
             admin,
             code_id,
@@ -486,6 +489,7 @@ mod tests {
         #[allow(deprecated)]
         let response = Reply {
             id,
+            payload,
             gas_used: 1234567,
             result: SubMsgResult::Ok(SubMsgResponse {
                 events: fake_events(reflect_addr.as_str()),

contracts/ibc-reflect/tests/integration.rs

@@ -91,11 +91,13 @@ fn connect(
         res.events[0]
     );
     let id = res.messages[0].id;
+    let payload = res.messages[0].payload.clone();
 
     // fake a reply and ensure this works
     #[allow(deprecated)]
     let response = Reply {
         id,
+        payload,
         gas_used: 1234567,
         result: SubMsgResult::Ok(SubMsgResponse {
             events: fake_events(&account),
@@ -153,6 +155,7 @@ fn proper_handshake_flow() {
     // and set up a reflect account
     assert_eq!(1, res.messages.len());
     let id = res.messages[0].id;
+    let payload = res.messages[0].payload.clone();
     if let CosmosMsg::Wasm(WasmMsg::Instantiate {
         admin,
         code_id,
@@ -178,6 +181,7 @@ fn proper_handshake_flow() {
     #[allow(deprecated)]
     let response = Reply {
         id,
+        payload,
         gas_used: 1234567,
         result: SubMsgResult::Ok(SubMsgResponse {
             events: fake_events(reflect_addr.as_str()),

contracts/reflect/schema/raw/execute.json

@@ -698,7 +698,7 @@
       ],
       "properties": {
         "gas_limit": {
-          "description": "Gas limit measured in [Cosmos SDK gas](https://github.com/CosmWasm/cosmwasm/blob/main/docs/GAS.md).",
+          "description": "Gas limit measured in [Cosmos SDK gas](https://github.com/CosmWasm/cosmwasm/blob/main/docs/GAS.md).\n\nSetting this to `None` means unlimited. Then the submessage execution can consume all gas of the current execution context.",
           "type": [
             "integer",
             "null"
@@ -715,6 +715,15 @@
         "msg": {
           "$ref": "#/definitions/CosmosMsg_for_CustomMsg"
         },
+        "payload": {
+          "description": "Some arbirary data that the contract can set in an application specific way. This is just passed into the `reply` entry point and is not stored to state. Any encoding can be used. If `id` is used to identify a particular action, the encoding can also be different for each of those actions since you can match `id` first and then start processing the `payload`.\n\nThe environment restricts the length of this field in order to avoid abuse. The limit is environment specific and can change over time. The initial default is 128 KiB.\n\nUnset/nil/null cannot be differentiated from empty data.\n\nOn chains running CosmWasm 1.x this field will be ignored.",
+          "default": "",
+          "allOf": [
+            {
+              "$ref": "#/definitions/Binary"
+            }
+          ]
+        },
         "reply_on": {
           "$ref": "#/definitions/ReplyOn"
         }

contracts/reflect/schema/raw/response_to_sub_msg_result.json

@@ -21,6 +21,15 @@
       "format": "uint64",
       "minimum": 0.0
     },
+    "payload": {
+      "description": "Some arbirary data that the contract set when emitting the `SubMsg`. This is just passed into the `reply` entry point and is not stored to state.\n\nUnset/nil/null cannot be differentiated from empty data.\n\nOn chains running CosmWasm 1.x this field is never filled.",
+      "default": "",
+      "allOf": [
+        {
+          "$ref": "#/definitions/Binary"
+        }
+      ]
+    },
     "result": {
       "$ref": "#/definitions/SubMsgResult"
     }

contracts/reflect/schema/reflect.json

@@ -708,7 +708,7 @@
         ],
         "properties": {
           "gas_limit": {
-            "description": "Gas limit measured in [Cosmos SDK gas](https://github.com/CosmWasm/cosmwasm/blob/main/docs/GAS.md).",
+            "description": "Gas limit measured in [Cosmos SDK gas](https://github.com/CosmWasm/cosmwasm/blob/main/docs/GAS.md).\n\nSetting this to `None` means unlimited. Then the submessage execution can consume all gas of the current execution context.",
             "type": [
               "integer",
               "null"
@@ -725,6 +725,15 @@
           "msg": {
             "$ref": "#/definitions/CosmosMsg_for_CustomMsg"
           },
+          "payload": {
+            "description": "Some arbirary data that the contract can set in an application specific way. This is just passed into the `reply` entry point and is not stored to state. Any encoding can be used. If `id` is used to identify a particular action, the encoding can also be different for each of those actions since you can match `id` first and then start processing the `payload`.\n\nThe environment restricts the length of this field in order to avoid abuse. The limit is environment specific and can change over time. The initial default is 128 KiB.\n\nUnset/nil/null cannot be differentiated from empty data.\n\nOn chains running CosmWasm 1.x this field will be ignored.",
+            "default": "",
+            "allOf": [
+              {
+                "$ref": "#/definitions/Binary"
+              }
+            ]
+          },
           "reply_on": {
             "$ref": "#/definitions/ReplyOn"
           }
@@ -1875,6 +1884,15 @@
           "format": "uint64",
           "minimum": 0.0
         },
+        "payload": {
+          "description": "Some arbirary data that the contract set when emitting the `SubMsg`. This is just passed into the `reply` entry point and is not stored to state.\n\nUnset/nil/null cannot be differentiated from empty data.\n\nOn chains running CosmWasm 1.x this field is never filled.",
+          "default": "",
+          "allOf": [
+            {
+              "$ref": "#/definitions/Binary"
+            }
+          ]
+        },
         "result": {
           "$ref": "#/definitions/SubMsgResult"
         }

contracts/reflect/src/contract.rs

@@ -434,6 +434,7 @@ mod tests {
         let _res = instantiate(deps.as_mut(), mock_env(), info, msg).unwrap();
 
         let id = 123u64;
+        let payload = Binary::from(b"my dear");
         let data = Binary::from(b"foobar");
         let events = vec![Event::new("message").add_attribute("signer", "caller-addr")];
         let gas_used = 1234567u64;
@@ -443,12 +444,13 @@ mod tests {
             data: Some(data.clone()),
             msg_responses: vec![],
         });
-        let subcall = Reply {
+        let the_reply = Reply {
             id,
+            payload,
             gas_used,
             result,
         };
-        let res = reply(deps.as_mut(), mock_env(), subcall).unwrap();
+        let res = reply(deps.as_mut(), mock_env(), the_reply).unwrap();
         assert_eq!(0, res.messages.len());
 
         // query for a non-existant id

contracts/reflect/tests/integration.rs

@@ -268,6 +268,7 @@ fn reply_and_query() {
     let _res: Response = instantiate(&mut deps, mock_env(), info, msg).unwrap();
 
     let id = 123u64;
+    let payload = Binary::from(b"my dear");
     let data = Binary::from(b"foobar");
     let events = vec![Event::new("message").add_attribute("signer", "caller-addr")];
     let gas_used = 1234567u64;
@@ -277,12 +278,13 @@ fn reply_and_query() {
         data: Some(data.clone()),
         msg_responses: vec![],
     });
-    let subcall = Reply {
+    let the_reply = Reply {
         id,
+        payload,
         gas_used,
         result,
     };
-    let res: Response = reply(&mut deps, mock_env(), subcall).unwrap();
+    let res: Response = reply(&mut deps, mock_env(), the_reply).unwrap();
     assert_eq!(0, res.messages.len());
 
     // query for a non-existant id

packages/std/src/results/response.rs

@@ -283,6 +283,7 @@ mod tests {
             messages: vec![
                 SubMsg {
                     id: 12,
+                    payload: Binary::new(vec![9, 8, 7, 6, 5]),
                     msg: BankMsg::Send {
                         to_address: String::from("checker"),
                         amount: coins(888, "moon"),
@@ -293,6 +294,7 @@ mod tests {
                 },
                 SubMsg {
                     id: UNUSED_MSG_ID,
+                    payload: Binary::default(),
                     msg: BankMsg::Send {
                         to_address: String::from("you"),
                         amount: coins(1015, "earth"),