Consider a document as 'unsaved' (dirty) when a linked image gets updated
Illustrator think that updating a link is not an operation.
This leads to problems with documents that use PDF-compatibility option.
Imagine you have an already saved document that have some linked images in it. You open it in Ai and then Edit a linked image in Photoshop. Make some changes in the image, save them in Ps, go to Ai and agree to update the link...
But Ai still considers the document as non-'dirty', as if no changes were made.
You can’t save the document and re-write the PDF content, to see these changes appear, say, in the InD document, where this Ai-documnet is placed in another document. You can only re-Save-As is, which is a not convenient operation. And if you close it — Ai does NOT offer you to save! And you have a document that you though HAVE an updated image in PDF-layer, while in fact it does NOT.
InDesign treats this right in same circumstances.
Again, if you had an .ai document that uses a link, that has been updated before you open this .ai document — Ai will tell you nothing about the change, and you have a file that has two version of image — one in Ai layer, and one in PDF one.
Very error prone.
The extension below feels like an overkill. Sure, this should be fixed, but the fastest workaround (although it requeues a habit) is to press Ctrl(Cmd)+Y twice, to toggle Preview mode. This is enough to trigger the 'dirty' status of the document.
Amazing... changing the mode, returning it to the one it used to be, is enough for 'changes!' flag, but updating a link — is not. Illustrator works in mysterious ways. And when it does not — even more mysterious...
It turns out there is even an extension made to solve this specific problem:
The illustrator file contains a link to the Photoshop file.
After changing the Photoshop file, the illustrator updates the link.
If I open the illustrator file and update the link, then if I close the illustrator file, it does not offer to save the file itself. And, therefore, the updated link is not saved in the illustrator file.
If this Illustrator file is linked somewhere, then the update is not visible in it.
Make it possible, after opening the file in illustrator and updating the link (without making changes to the file, just updating the link), so that when closing the illustrator SAVES the file.
Sorry for my English