Bug 634269: [Subcontracting] Fix second return from subcontractor failing after first posted

[ChethanT]

Problem

Cannot create a second return from subcontractor after the first return transfer order is posted and deleted. The error is:

Transfer-from Code and Transfer-to Code cannot be the same

Root Cause

The OnAfterDeleteEvent subscriber in SubcTransferLineExt.Codeunit.al calls UpdateLocationCodeInProdOrderCompAfterDeleteTransferLine for ALL transfer line deletions, including return transfer lines. This procedure was designed only for outbound transfer cleanup (restoring the component location from SUBC back to MAIN when an outbound transfer is deleted/cancelled).

When it fires for a return line deletion (after posting), it:

1. Restores ProdOrderComponent."Location Code" to the Original Location Code
2. Clears "Subc. Original Location Code" to ''

On the next return attempt, the system sees Orig Location Code = '', sets it to the current (corrupted) location, and computes Transfer-from = Transfer-to = SUBC → error.

Fix

Added a guard in OnAfterDeleteEvent:

if Rec."Subc. Return Order" then
    exit;

This ensures location restoration only runs for outbound transfer line deletions, not return lines.

Testing

New test codeunit 149917 that:

1. Creates outbound transfer, posts it
2. Creates first return, posts it (return transfer deleted)
3. Creates second return — verifies it succeeds without error

Fixes AB#634269