Re: [PATCH] builtin-blame.c: Use utf8_strwidth for author's names

On Sun, Feb 01, 2009 at 10:48:51PM -0800, Junio C Hamano wrote:

quoted

I do not know what encoding the author is at that point, but if you cannot 
be sure that it is UTF-8, using utf8_strwidth() is just as wrong as the 
current code, IMHO.

That is true, but then we are not losing anything.

This codepath is not about the payload (the contents of the files) but the
author name part of the commit log message, and UTF-8 would probably be
the only sensible encoding to standardize on.

If your project uses UTF-8 for everybody, great, we will align them better
than we did before.  If not, sorry, you will get a different misaligned
names.

That assumes utf8_width() does not barf when fed an invalid byte sequence,
but I did not think it is that fragile (I didn't actually audit the
codepath, though).

We should be able to know the encoding (we call reencode_commit_message,
but we don't bother to save the result). It should be trivial to do:

int strwidth(const char *s, const char *encoding)
{
  if (!strcmp(encoding, "utf-8"))
    return utf8_strwidth(s);
  /* ideally, else if (some_other_encoding_family) */
  else
    return strlen(s);
}

Then utf-8 is fixed, and other encodings keep identical behavior (and
don't even waste cycles on utf-8 decoding). And it should be obvious to
anyone who wants to add a width detector for their pet encoding where it
should go.

-Peff