Correct implementation

aptos-move/framework/aptos-stdlib/sources/fixed_point64.move

@@ -56,6 +56,19 @@ module aptos_std::fixed_point64 {
         ensures result.value == x.value + y.value;
     }
 
+    /// Returns x / y. The result cannot be greater than MAX_U128.
+    public fun divide(x: FixedPoint64, y: FixedPoint64): FixedPoint64 {
+        let x_raw = get_raw_value(x);
+        let y_raw = get_raw_value(y);
+        // If it is divisable, return the result. If not, return the result + 1.
+        let result = (x_raw as u256) / (y_raw as u256);
+        if ((x_raw as u256) % (y_raw as u256) != 0) {
+            result = result + 1;
+        };
+        assert!(result <= MAX_U128, ERATIO_OUT_OF_RANGE);
+        create_from_raw_value((result as u128))
+    }
+
     /// Multiply a u128 integer by a fixed-point number, truncating any
     /// fractional part of the product. This will abort if the product
     /// overflows.
@@ -95,6 +108,7 @@ module aptos_std::fixed_point64 {
         create_from_raw_value((unscaled_product as u128))
     }
 
+
     /// Divide a u128 integer by a fixed-point number, truncating any
     /// fractional part of the quotient. This will abort if the divisor
     /// is zero or if the quotient overflows.

aptos-move/framework/supra-framework/sources/pbo_delegation_pool.move

@@ -122,6 +122,7 @@ module supra_framework::pbo_delegation_pool {
     use aptos_std::table::{Self, Table};
     use aptos_std::smart_table::{Self, SmartTable};
     use aptos_std::fixed_point64::{Self, FixedPoint64};
+    use aptos_std::math64::min;
 
     use supra_framework::coin::Coin;
     use supra_framework::account;
@@ -1778,12 +1779,15 @@ module supra_framework::pbo_delegation_pool {
             cfraction = fixed_point64::add(cfraction, next_fraction);
             last_unlocked_period = last_unlocked_period + 1;
         };
-
-        let final_fraction= *vector::borrow(&unlock_schedule.schedule, schedule_length - 1);
-        // Fast foward calculation to current period and don't update last_unlocked_period since it is not used anymore
-        cfraction = fixed_point64::add(cfraction, fixed_point64::multiply_u128_return_fixpoint64((unlock_periods_passed - last_unlocked_period as u128), final_fraction));
-        cfraction = fixed_point64::min(cfraction, one);
-
+        if (last_unlocked_period < unlock_periods_passed && fixed_point64::less(cfraction, one)) {
+            let final_fraction= *vector::borrow(&unlock_schedule.schedule, schedule_length - 1);
+            // Determine how many periods is needed
+            let periods_needed = min(unlock_periods_passed - last_unlocked_period,
+                ((fixed_point64::get_raw_value(fixed_point64::divide(fixed_point64::sub(one, cfraction), final_fraction)) as u64) )
+            );
+            // Acclerate calculation to current period and don't update last_unlocked_period since it is not used anymore
+            cfraction = fixed_point64::add(cfraction, fixed_point64::multiply_u128_return_fixpoint64((periods_needed as u128), final_fraction));
+        };
         unlock_schedule.cumulative_unlocked_fraction = cfraction;
         unlock_schedule.last_unlock_period = unlock_periods_passed;
         let unlockable_amount = cached_unlockable_balance(delegator_addr, pool_address);

aptos-move/framework/supra-framework/sources/vesting_without_staking.move

@@ -496,8 +496,8 @@ module supra_framework::vesting_without_staking {
 
         // Index is 0-based while period is 1-based so we need to subtract 1.
         while (last_completed_period >= next_period_to_vest && vesting_record.left_amount > 0 && next_period_to_vest <= vector::length(schedule)) {
-            // let schedule_index = next_period_to_vest - 1;
-            let vesting_fraction = *vector::borrow(schedule, vector::length(schedule) - 1);
+            let schedule_index = next_period_to_vest - 1;
+            let vesting_fraction = *vector::borrow(schedule, schedule_index);
             vest_transfer(vesting_record, signer_cap, beneficiary, vesting_fraction);
             emit_event(&mut vesting_contract.vest_events,
                 VestEvent {
@@ -510,19 +510,29 @@ module supra_framework::vesting_without_staking {
             next_period_to_vest = next_period_to_vest + 1;
         };
 
-        let final_fraction = *vector::borrow(schedule, vector::length(schedule) - 1);
-        let total_fraction = fixed_point32::multiply_u64_return_fixpoint32((last_completed_period - next_period_to_vest ), final_fraction);
-        // We don't need to check vesting_record.left_amount > 0 because vest_transfer will handle that.
-        vest_transfer(vesting_record, signer_cap, beneficiary, total_fraction);
-        next_period_to_vest = last_completed_period + 1;
-        emit_event(&mut vesting_contract.vest_events,
-            VestEvent {
-                admin: vesting_contract.admin,
-                shareholder_address: shareholder_address,
-                vesting_contract_address: contract_address,
-                period_vested: next_period_to_vest,
-            },
-        );
+        if(last_completed_period >= next_period_to_vest && vesting_record.left_amount > 0) {
+            let final_fraction = *vector::borrow(schedule, vector::length(schedule) - 1);
+            // Determine how many periods is needed based on the left_amount
+            let periods_need_used_up_amount = if (vesting_record.left_amount % fixed_point32::multiply_u64(vesting_record.init_amount, final_fraction) == 0) {
+                vesting_record.left_amount / fixed_point32::multiply_u64(vesting_record.init_amount, final_fraction)
+            } else {
+                vesting_record.left_amount / fixed_point32::multiply_u64(vesting_record.init_amount, final_fraction) + 1
+            };
+            let periods_needed =
+                min(periods_need_used_up_amount, last_completed_period - next_period_to_vest + 1);
+            let total_fraction = fixed_point32::multiply_u64_return_fixpoint32(periods_needed, final_fraction);
+            // We don't need to check vesting_record.left_amount > 0 because vest_transfer will handle that.
+            vest_transfer(vesting_record, signer_cap, beneficiary, total_fraction);
+            next_period_to_vest = next_period_to_vest + periods_needed;
+            emit_event(&mut vesting_contract.vest_events,
+                VestEvent {
+                    admin: vesting_contract.admin,
+                    shareholder_address: shareholder_address,
+                    vesting_contract_address: contract_address,
+                    period_vested: next_period_to_vest,
+                },
+            );
+        };
 
         //update last_vested_period for the shareholder
         vesting_record.last_vested_period = next_period_to_vest - 1;