[Bug][Extensibility][MultiObjects][Subscription Billing] Deferrals extensibility and multiple critical fixes

[miljance]

Describe the issue

This issue addresses multiple critical bugs and extensibility gaps in the Microsoft Subscription Billing deferrals functionality. The current implementation has the following issues:

1. Extensibility: Five core deferral objects need integration points (events) for ISV extensions to customize behavior during deferral creation and release processes.

2. Missing Posting Groups in Deferrals: Contract deferrals cannot be released when the original posted documents are unavailable (e.g., in data migration scenarios), because posting group information is retrieved from posted invoice/credit memo lines instead of being stored in the deferral entries.

3. Zero-Amount Deferrals: The system creates unnecessary deferral entries and G/L postings for contract lines with 0.00 amounts, leading to excessive ledger entries with no financial impact.

4. Inconsistent Partial Period Handling: Vendor contract deferrals handle partial billing periods inconsistently—some invoices are deferred based on full months while others are calculated daily, causing incorrect revenue recognition.

5. Credit Memo Deferral Gap: Credit memos with amounts exceeding the original invoice amount do not generate corresponding deferral entries, resulting in incomplete revenue recognition.

6. Double Deferral Generation: When both contract-based deferrals and standard deferral codes are used, deferrals are incorrectly created in both systems simultaneously.

Expected behavior

Extensibility Enhancements

Objects requiring extensibility events:

• Report 8051 "Contract Deferrals Release"
• Table 8066 "Cust. Sub. Contract Deferral"
• Table 8072 "Vend. Sub. Contract Deferral"
• Report 8052 "Cust. Contr. Def. Analysis"
• Report 8053 "Vend Contr. Def. Analysis"

Required events:

1. OnBeforeInsertGenJournalLine event in ReleaseContractDeferral/related functions to allow ISVs to skip journal line insertion based on custom logic
2. OnAfterInitFromSalesLine event in InitFromSalesLine procedure
3. OnAfterInitFromPurchaseLine event in InitFromPurchaseLine procedure

Bug Fixes Expected Behavior

Task 2 - Posting Groups Storage:

• Add "Gen. Bus. Posting Group" and "Gen. Prod. Posting Group" fields to both deferral tables
• Populate these fields during deferral entry creation from the invoice line
• Modify release logic to use stored posting groups instead of retrieving from posted documents
• Implement data upgrade to retrospectively fill posting groups from existing document lines

Task 3 - Zero-Amount Prevention:

• Skip deferral entry creation when the deferral amount equals 0.00
• Prevent G/L postings for zero-amount deferrals during release
• Reduce unnecessary ledger entries significantly in contracts with multiple zero-amount lines

Task 4 - Consistent Partial Period Calculation:

• Apply consistent day-based calculation for all partial billing periods in vendor contracts
• Ensure both the first and last month of multi-month periods are calculated proportionally based on actual days
• Monthly amounts should match deferral amounts when billing covers full calendar months

Task 5 - Credit Memo Deferral Handling:

• Generate negative deferral entries for all credit memos, regardless of amount
• Ensure credit memos that exceed original invoice amounts create corresponding deferral adjustments
• Maintain complete and accurate deferral schedules reflecting all revenue adjustments

Task 6 - Prevent Double Deferrals:

• Block "Deferral Code" field on Sales Line and Purchase Line when contract deferrals are enabled
• Field should only be editable when:
  • Contract line has "Create Contract Deferrals" = No, OR
  • Contract line has "Create Contract Deferrals" = Contract-dependent AND contract header has "Create Contract Deferrals" = No

Steps to reproduce

Task 2 - Missing Posting Groups

1. Import contract deferral data from legacy system (without corresponding posted documents)
2. Navigate to Contract Deferrals Release (Report 8051)
3. Set posting date and post-until date
4. Execute release process
5. Result: Error occurs because system cannot retrieve posting groups from non-existent posted invoice lines

Task 3 - Zero-Amount Deferrals

1. Create a Customer Subscription Contract with 11 lines:
   • 1 line with monthly amount (e.g., €100)
   • 10 lines with 0.00 amount (asset subscriptions)
2. Enable "Contract Deferrals" = Yes
3. Create and post contract invoice
4. Execute Contract Deferral Release
5. Result:
   • 11 contract deferrals created (11 × 12 = 132 entries for a year)
   • 22 G/L entries generated (2 with value, 20 with 0.00)

Task 4 - Partial Period Inconsistency

1. Create vendor subscription contract with annual billing
2. Post purchase invoice 1 with period 01.05.2025 - 15.06.2025
3. Post purchase invoice 2 with period 16.06.2025 - 31.07.2025
4. Review generated deferrals
5. Result:
   • Invoice 1: Amount divided equally between May and June (ignores partial June)
   • Invoice 2: Amount distributed daily across months (correct partial period handling)

Task 5 - Credit Memo Deferrals

1. Create customer subscription contract with deferrals enabled
2. Post invoice for €1,000
3. Create credit memo for €1,200 (exceeding original invoice)
4. Post credit memo
5. Review contract deferrals
6. Result: Only the €1,000 invoice appears in deferrals; no €1,200 credit memo entry exists

Task 6 - Double Deferrals

1. Create Customer Subscription Contract and Subscription
2. Assign subscription to contract
3. Create contract invoice
4. On the invoice line, assign a Deferral Code (standard BC deferrals)
5. Post the contract invoice
6. Check both:
   • Subscription Billing module → Contract Deferrals
   • Financial Management → Standard Deferrals
7. Result: Deferrals created in BOTH locations, causing double revenue deferral

Additional context

No response

I will provide a fix for a bug

• I will provide a fix for a bug