[CWuestefeld]

Years ago I reported a bug in a VB function, something to do with date calculations. I spent quite a while on the phone with them, feeling like I was banging my head against a wall. They readily admitted that the output of their function was wrong, yet steadfastly maintained that they would not fix it because other programs might depend on that incorrect output.

If the answer to any bug report is that the buggy behavior is now the baseline standard, what's the point in reporting any bugs?

[bombcar]

Excel famously has a date calculator bug that cannot be fixed without breaking spreadsheets everywhere (which of course now expect the bug).

[grishka]

This all can be worked around given enough will. Excel files do have a format version number in them somewhere, right? I'm sure they do. So support the old behavior for older files, and the new one for the newer ones. All files created with the new version of Excel won't be affected by that bug, but the older ones, that might rely on it, won't break either.

[wiseleo]

It gets worse. This workaround is also in VBA, which has an enormous install base.

Books on Excel programming explicitly call out this issue. This is one thing I definitely would not want fixed.

You will break countless workflows that have operated for decades.

[bombcar]

And even better non-excel spreadsheets have to know the bug and imitate it when opening excel docs.