It's not that it's hard. It's just that -any- noise subtracts from readability.
Which means a patch that -only- does the minimum required for adding the error-check will
always be more readable than one that does that, plus fix the formatting of the surrounding 5
So your advice adds up to, essentially: NEVER FIX STYLE-ISSUES.
Which is overdoing it. I agree that it's *often* a bad thing to do style-change. But there's
two important readability-issues here:
One is the readability of the patch. That is always better with zero style-changes.
The second is the readability of the code after the patch is applied. If that is sufficiently
improved by doing style-fixes, those may be worthwhile even though it hurts the patch.