propagate returndata of revert/success call, not exceptional fail

crates/evm/src/call_helpers.cairo

@@ -99,10 +99,20 @@ impl CallHelpersImpl of CallHelpers {
         let result = EVMTrait::process_message(message, ref self.env);
         self.merge_child(@result);
 
-        if result.is_success() {
-            self.stack.push(1)?;
-        } else {
-            self.stack.push(0)?;
+        match result.status {
+            ExecutionResultStatus::Success => {
+                self.return_data = result.return_data;
+                self.stack.push(1)?;
+            },
+            ExecutionResultStatus::Revert => {
+                self.return_data = result.return_data;
+                self.stack.push(0)?;
+            },
+            ExecutionResultStatus::Exception => {
+                // If the call has halted exceptionnaly, the return_data is emptied.
+                self.return_data = [].span();
+                self.stack.push(0)?;
+            },
         }
 
         // Get the min between len(return_data) and call_ctx.ret_size.

crates/evm/src/create_helpers.cairo

@@ -149,6 +149,7 @@ impl CreateHelpersImpl of CreateHelpers {
                 self.stack.push(0)?;
             },
             ExecutionResultStatus::Exception => {
+                // returndata is emptied in case of exception
                 self.return_data = [].span();
                 self.stack.push(0)?;
             },

crates/evm/src/model/vm.cairo

@@ -154,6 +154,7 @@ impl VMImpl of VMTrait {
                 self.return_data = *child.return_data;
             },
             ExecutionResultStatus::Revert => { self.gas_left += *child.gas_left; },
+            // If the call has halted exceptionnaly, the gas is not returned.
             ExecutionResultStatus::Exception => {}
         };
     }