Global padding for bundle

src/builder.rs

@@ -464,6 +464,18 @@ impl Builder {
         i64::try_from(value_balance).and_then(|i| V::try_from(i).map_err(|_| value::OverflowError))
     }
 
+    /// Returns the number of actions to add to this bundle in order to contain at least MIN_ACTION actions.
+    fn num_missing_actions(&self) -> usize {
+        let num_actions = [self.spends.len(), self.recipients.len()]
+            .iter()
+            .max()
+            .cloned()
+            .unwrap();
+        (num_actions < MIN_ACTIONS)
+            .then(|| MIN_ACTIONS - num_actions)
+            .unwrap_or(0)
+    }
+
     /// Builds a bundle containing the given spent notes and recipients.
     ///
     /// The returned bundle will have no proof or signatures; these can be applied with
@@ -480,11 +492,11 @@ impl Builder {
         {
             let num_spends = spends.len();
             let num_recipients = recipients.len();
-            let num_actions = [num_spends, num_recipients, MIN_ACTIONS]
-                .iter()
-                .max()
-                .cloned()
-                .unwrap();
+            let mut num_actions = [num_spends, num_recipients].iter().max().cloned().unwrap();
+            // We might have to add dummy/split actions only for the first asset to reach MIN_ACTIONS.
+            pre_actions
+                .is_empty()
+                .then(|| num_actions += self.num_missing_actions());
 
             let first_spend = spends.first().cloned();
 

tests/zsa.rs

@@ -408,7 +408,7 @@ fn zsa_issue_and_transfer() {
         ],
         vec![],
         anchor,
-        4,
+        2,
         &keys,
     )
     .unwrap();
@@ -436,7 +436,7 @@ fn zsa_issue_and_transfer() {
         ],
         vec![],
         native_anchor,
-        5,
+        4,
         &keys,
     )
     .unwrap();
@@ -468,7 +468,7 @@ fn zsa_issue_and_transfer() {
         ],
         vec![],
         anchor_t7,
-        4,
+        2,
         &keys,
     )
     .unwrap();
@@ -489,7 +489,7 @@ fn zsa_issue_and_transfer() {
             ],
             vec![],
             anchor_t7,
-            4,
+            2,
             &keys,
         )
         .unwrap();