Full file name in Relink dialog window

As ​@Manan Joshi already said, that text field in the dialog is provided by Apple. But Adobe doesn’t seem to use it efficiently (possibly because nobody ever asked).

You can test the behavior of the message field by running this AppleScript script in Script Editor:
 

choose file with prompt "some multiline message some multiline message.\rsome multiline message some multiline message\r​​​​​​​some multiline message some multiline message​​​​​​​"

The problem with this field is that if you pass a single-line message to it that’s too long, it will make the dialog expand to accommodate the text and the user won’t be able to shrink the dialog:

 

So there’s a valid reason why Adobe decided to truncate long paths.

Ideally, they could make it multi-line. For example, a truncated path on the first line plus only the file name on the second line.

You can post feature requests here:
https://indesign.uservoice.com/forums/601021-adobe-indesign-feature-requests
​​​​​​​
Also, custom scripts can be created for relinking with full control of the way you display the file names.

This would be macOS in my assessment. This is an OS file picker that we see. So the Adobe code most probably would be giving it the path. How to show that path, truncation etc would be handled by the OS itself. Unless there is a way to configure it