[Bug]: [E-Document] PDF preview factbox writes to Tenant Media on every OnAfterGetCurrRecord of purchase invoice pages

Describe the issue

PR #9145 hosts page 6111 "Inbound E-Doc. Picture" as a factbox on Purchase Invoice (51), Purchase Invoices (9308), Posted Purchase Invoice (138) and Posted Purchase Invoices (146). Its OnAfterGetCurrRecord → LoadPdfImage() ends with:

TempMediaRepository.Image.ImportStream(ImageStream, EDocDataStorageImageDescriptionLbl, 'image/png');

TempMediaRepository is temporary, but Media.ImportStream always inserts the media object into system table 2000000184 "Tenant Media" – the temporary record only holds the GUID reference (docs). Displaying a purchase invoice is now a database write, with three consequences:

1. A write transaction is opened. Code that is not allowed inside a write transaction fails until the next commit. Our test opens the Posted Purchase Invoice card and invokes CancelInvoice; it now fails in codeunit "Correct Posted Purch. Invoice", CreateCreditMemo():

   if not CODEUNIT.Run(CODEUNIT::"Correct Posted Purch. Invoice", PurchInvHeader) then begin

The following C/AL functions are limited during write transactions because one or more tables will be locked. [...] Codeunit.Run is allowed in write transactions only if the return value is not used.

The test passed before this PR. Any partner test that runs Cancel/Correct (or anything else using Codeunit.Run with a return value / RunModal) through the Posted Purchase Invoice test page is affected.

2. Orphaned Tenant Media rows. Every render inserts a "Tenant Media" record that nothing references and nothing deletes. PdfLoaded is never set to true, so the "already loaded" guard is dead code: the PDF blob is re-read, re-rendered to PNG and re-imported on every OnAfterGetCurrRecord / CurrPage.Update – on the list pages, on every row change.

3. Not limited to linked invoices. The part has no SubPageLink and the host calls SetRecFilterByEDocDataStorageEntryNo() unconditionally, so without a filter the part is positioned on the first "E-Doc. Data Storage" record in the table and renders that one. Our test invoice has no E-Document at all and still fails.

Expected behavior

Opening a purchase invoice (posted or not) does not write to the database. Render the preview once and persist it (e.g. a Media field on "E-Doc. Data Storage" populated when the E-Document is received), so the factbox only reads. Cancel/Correct from the Posted Purchase Invoice card works without an intermediate Commit(), as before.

Steps to reproduce

Precondition: at least one "E-Doc. Data Storage" record with File Format = PDF exists in the database.

PurchInvHeader.Get(LibraryPurchase.PostPurchaseDocument(PurchaseHeader, true, true));
Commit();

PostedPurchaseInvoiceCard.OpenEdit();
PostedPurchaseInvoiceCard.GoToRecord(PurchInvHeader);
LibraryDialogHandler.SetExpectedConfirm(CancelPostedInvoiceQst, true);
LibraryDialogHandler.SetExpectedConfirm(OpenPostedCreditMemoQst, false);
PostedPurchaseInvoiceCard.CancelInvoice.Invoke(); // <- write-transaction error

Or simply: count "Tenant Media" records, open a posted purchase invoice card / scroll the list, count again.

Additional context

• PR #9145 states "No table schema change; no new stored data" – the Tenant Media inserts contradict that.
• In the web client the transaction is committed at the end of every server call, so interactive users only see the data growth, not the error; tests and transactional code hit the error.
• Files: InboundEDocPicture.Page.al, pageextension 6146 "E-Doc. Posted Purch. Inv."
• Version: 29.0 (main)

I will provide a fix for a bug

• I will provide a fix for a bug

Start with InboundEDocPicture.Page.al and pageextension 6146 "E-Doc. Posted Purch. Inv.", then trace OnAfterGetCurrRecord, LoadPdfImage(), and TempMediaRepository.Image.ImportStream. Run the Posted Purchase Invoice reproduction and inspect Tenant Media before and after opening or scrolling pages; done means preview access causes no database write and CancelInvoice no longer hits the write-transaction error.