Add new error if stake delegation is below the minimum (#25709)

programs/stake/src/stake_instruction.rs

@@ -3886,7 +3886,10 @@ mod tests {
         ];
         for (stake_delegation, expected_result) in &[
             (minimum_delegation, Ok(())),
-            (minimum_delegation - 1, Err(StakeError::InsufficientStake)),
+            (
+                minimum_delegation - 1,
+                Err(StakeError::InsufficientDelegation),
+            ),
         ] {
             for stake_state in &[
                 StakeState::Initialized(meta),
@@ -7029,7 +7032,7 @@ mod tests {
         fn test_behavior_withdrawal_then_redelegate_with_less_than_minimum_stake_delegation() {
             do_test_behavior_withdrawal_then_redelegate_with_less_than_minimum_stake_delegation(
                 new_feature_set(),
-                Err(StakeError::InsufficientStake.into()),
+                Err(StakeError::InsufficientDelegation.into()),
             );
         }
         #[test]

programs/stake/src/stake_state.rs

@@ -1034,7 +1034,7 @@ fn validate_delegated_amount(
         || feature_set.is_active(&feature_set::stake_raise_minimum_delegation_to_1_sol::id()))
         && stake_amount < crate::get_minimum_delegation(feature_set)
     {
-        return Err(StakeError::InsufficientStake.into());
+        return Err(StakeError::InsufficientDelegation.into());
     }
     Ok(ValidatedDelegatedInfo { stake_amount })
 }

sdk/program/src/stake/instruction.rs

@@ -57,6 +57,9 @@ pub enum StakeError {
         "stake account has not been delinquent for the minimum epochs required for deactivation"
     )]
     MinimumDelinquentEpochsForDeactivationNotMet,
+
+    #[error("delegation amount is less than the minimum")]
+    InsufficientDelegation,
 }
 
 impl<E> DecodeError<E> for StakeError {