2
Dalai
No, wrong rabbit hole
The file BORG52 has problems with is just approx. 214 KB in size. Just did a quick test (two files with 17 KB each, so in total only ~34 KB), it really seems to be about the line length. Go beyond a line length of somewhere between 16000 and 17000 characters (or perhaps bytes? I haven't tested with multi-byte characters), and no edit mode for ya...
It still seems to be a limitation though. If you compare two almost identical files with such very long lines, where only a few characters differ between the very long line(s) of the file, the file compare tool is not able to only highlight the differing characters, but highlights the whole very long line as different.
I find it curious, though, that the edit mode is disabled even though the viewer/editor component can still render the entire very long lines without issues, as it seems. The diff highlighting being limited should not affect the function of the editor, no?