+ case '%': case '+': case ',': case '-': case '.': case '/':
+ case '0': case '1': case '2': case '3': case '4': case '5':
+ case '6': case '7': case '8': case '9': case ':': case '=':
+ case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
+ case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
+ case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
+ case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
+ case 'Y': case 'Z': case ']': case '_': case 'a': case 'b':
+ case 'c': case 'd': case 'e': case 'f': case 'g': case 'h':
+ case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
+ case 'o': case 'p': case 'q': case 'r': case 's': case 't':
+ case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
+ case '{': case '}':
+ /* These characters don't cause problems, no matter what the
+ quoting style is. They cannot start multibyte sequences. */
+ break;
+
+ default:
+ /* If we have a multibyte sequence, copy it until we reach
+ its end, find an error, or come back to the initial shift
+ state. For C-like styles, if the sequence has
+ unprintable characters, escape the whole sequence, since
+ we can't easily escape single characters within it. */
+ {
+ /* Length of multibyte sequence found so far. */
+ size_t m = 0;
+
+ int printable = 1;
+ mbstate_t mbstate;
+ memset (&mbstate, 0, sizeof mbstate);
+
+ if (argsize == (size_t) -1)
+ argsize = strlen (arg);
+
+ do
+ {
+ wchar_t w;
+ size_t bytes = mbrtowc (&w, &arg[i + m],
+ argsize - (i + m), &mbstate);
+ if (bytes == 0)
+ break;
+ else if (bytes == (size_t) -1)
+ {
+ printable = 0;
+ break;
+ }
+ else if (bytes == (size_t) -2)
+ {
+ printable = 0;
+ while (i + m < argsize && arg[i + m])
+ m++;
+ break;
+ }
+ else
+ {
+ if (! iswprint (w))
+ printable = 0;
+ m += bytes;
+ }
+ }
+ while (! mbsinit (&mbstate));
+
+ if (m <= 1)
+ {
+ /* Escape a unibyte character like a multibyte
+ sequence if using backslash escapes, and if the
+ character is not printable. */
+ m = backslash_escapes && ! ISPRINT (c);
+ printable = 0;
+ }
+
+ if (m)
+ {
+ /* Output a multibyte sequence, or an escaped
+ unprintable unibyte character. */
+ size_t imax = i + m - 1;
+
+ for (;;)
+ {
+ if (backslash_escapes && ! printable)
+ {
+ STORE ('\\');
+ STORE ('0' + (c >> 6));
+ STORE ('0' + ((c >> 3) & 7));
+ c = '0' + (c & 7);
+ }
+ if (i == imax)
+ break;
+ STORE (c);
+ c = arg[++i];
+ }