char *⏎
get_4 (struct base64_decode_context *ctx,⏎
       char const *restrict *in, char const *restrict in_end,⏎
       size_t *n_non_newline)⏎
{⏎
  if (ctx->i == 4)⏎
    ctx->i = 0;⏎
⏎
  if (ctx->i == 0)⏎
    {⏎
      char const *t = *in;⏎
      if (4 <= in_end - *in && memchr (t, '\n', 4) == NULL)⏎
        {⏎
          /* This is the common case: no newline.  */⏎
          *in += 4;⏎
          *n_non_newline = 4;⏎
          return (char *) t;⏎
        }⏎
    }⏎
⏎
  {⏎
    /* Copy non-newline bytes into BUF.  */⏎
    char const *p = *in;⏎
    while (p < in_end)⏎
      {⏎
        char c = *p++;⏎
        if (c != '\n')⏎
          {⏎
            ctx->buf[ctx->i++] = c;⏎
            if (ctx->i == 4)⏎
              break;⏎
          }⏎
      }⏎
⏎
    *in = p;⏎
    *n_non_newline = ctx->i;⏎
    return ctx->buf;⏎
  }⏎
}⏎