Scotland's People has a section on Mac in its page on surnames (as you'd expect). On their orthography It just says "Mac surnames were also written as Mc, Mhic, or M’." (Elsewhere I have found mention of M'c as well, as a use of the standard convention for omitted letters, though that may be a misunderstanding.) In other words the name element is, and is always pronounced, Mac; the alternatives are contractions in writing.
So I don't think that M'Evoy should be seen as a mistake. It's more an orthographic convention with limited usage that isn't well understood now. That leads to the specific problem that the symbol that was a curl facing right may get converted into a curl facing left or a straight apostrophe. You could justifiably replace it with Mc, with a choice of vertical position for the "c", but doing that automatically would pose all the usual difficulties (though AI could likely cope).
Of course what used to be alternative ways of writing a name can become fixed, and people get very attached to one way of writing their own surname. So my saying it doesn't matter may not satisfy some "owners" of those names. It's a bit like Miss, Mrs., (and earlier Mris.), which were all once ways of writing Mistress. So it doesn't really matter which I write, does it? Well, maybe...
So I don't think that M'Evoy should be seen as a mistake. It's more an orthographic convention with limited usage that isn't well understood now. That leads to the specific problem that the symbol that was a curl facing right may get converted into a curl facing left or a straight apostrophe. You could justifiably replace it with Mc, with a choice of vertical position for the "c", but doing that automatically would pose all the usual difficulties (though AI could likely cope).
Of course what used to be alternative ways of writing a name can become fixed, and people get very attached to one way of writing their own surname. So my saying it doesn't matter may not satisfy some "owners" of those names. It's a bit like Miss, Mrs., (and earlier Mris.), which were all once ways of writing Mistress. So it doesn't really matter which I write, does it? Well, maybe...
